ORCID Profile
0000-0002-5332-2789
Current Organisation
Canadian Blood Services
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Publisher: MDPI AG
Date: 27-09-2022
DOI: 10.3390/V14102126
Abstract: Humans interact with virus-infected animal hosts, travel globally, and maintain social networks that allow for novel viruses to emerge and develop pandemic potential. There are key lessons-learned from the coronavirus diseases 2019 (COVID-19) pandemic that blood operators can apply to the next pandemic. Warning signals to the COVID-19 pandemic included outbreaks of Severe acute respiratory syndrome-related coronavirus-1 (SARS-CoV-1) and Middle East respiratory syndrome-related coronavirus (MERS-CoV) in the prior two decades. It will be critical to quickly determine whether there is a risk of blood-borne transmission of a new pandemic virus. Prior to the next pandemic blood operators should be prepared for changes in activities, policies, and procedures at all levels of the organization. Blood operators can utilize “Plan-Do-Study-Act” cycles spanning from: vigilance for emerging viruses, surveillance activities and studies, operational continuity, donor engagement and trust, and laboratory testing if required. Occupational health and donor safety issues will be key areas of focus even if the next pandemic virus is not transfusion transmitted. Blood operators may also be requested to engage in new activities such as the development of therapeutics or supporting public health surveillance activities. Activities such as scenario development, tabletop exercises, and drills will allow blood operators to prepare for the unknowns of the next pandemic.
Publisher: Wiley
Date: 02-2022
DOI: 10.1111/TRF.16786
Publisher: Wiley
Date: 10-06-2021
DOI: 10.1111/VOX.13164
Abstract: Chagas disease, caused by Trypanosoma cruzi , is endemic to Mexico, Central and South America. While initially limited to the Americas, emigration of infected persons triggered geographically broader blood safety challenges. To mitigate transfusion‐transmitted Chagas (TTC), transfusion services implemented approaches including risk factor questions and serologic testing. We sought to understand and compare strategies in non‐endemic countries. Transfusion services in International Society of Blood Transfusion (ISBT)‐affiliated organizations and members of the ISBT Working Party on Transfusion‐Transmitted Infectious Diseases were invited to complete an online survey on T. cruzi mitigation strategies. The survey queried about cases of TTC, risk factors, testing methodology, educational materials, pathogen reduction, donor roduct management, donor deferral and perceived public health concerns surrounding TTC. Responses were received from 27 institutions in 22 countries. Most countries (77.3%) reported no historical TTC cases, while 18.2% reported 1–5 cases and 4.5% reported 6–10 cases. Concern about Chagas among the general public and public health authorities was low, but 12 of 25 blood centres reported moderate/high concern. Overall, 17 countries mitigated for TTC: 15 used risk factor questions and 10tested for T. cruzi antibodies. Ten countries used pathogen reduction but not specifically to prevent TTC. While Chagas is rarely cited as a public health concern, blood centres in many non‐endemic countries, including those outside the Americas, implemented measures to mitigate risk. Mitigation focussed on risk factors associated with Latin American immigrants and serologic testing. Thus, despite the rarity of TTC, many non‐endemic countries continue to address it as an ongoing blood safety risk.
Publisher: American College of Physicians
Date: 10-2021
DOI: 10.7326/M20-7003
Publisher: Wiley
Date: 08-2020
DOI: 10.1111/TRF.15977
Publisher: Wiley
Date: 06-2016
DOI: 10.1111/TRF.13555
Publisher: Wiley
Date: 31-07-2017
DOI: 10.1111/TRF.14247
Abstract: The recent spread of the Zika virus to the Americas and the recognition that it can cause severe disease in the developing fetus has prompted the adoption of measures to mitigate the risk that this virus might pose to transfusion safety. In nonendemic countries, the risk to transfusion results from donors traveling to an endemic region. Canada implemented a 21-day temporary deferral for prospective donors who traveled to such regions. We present the rationale for this policy, including a quantitative risk assessment supported by a Monte Carlo simulation. The model considered the following parameters, each with specified values and ranges: the probability that a donor recently returned from a Zika-endemic region, the duration of travel to this region, the daily risk of acquiring Zika while in an endemic region, and the incubation and viremic periods. We ran the simulation 20 times, each with 10 million iterations. In the absence of any travel deferral, 32 donors (range, 20-46 donors) would be able to donate while still being at risk of transmitting Zika, corresponding to a rate of 1:312,500 (range, 1:217,000 to 1:500,000). None of these donors would be viremic beyond 21 days after returning from their travel, with a risk estimated at less than 1:200,000,000. A 21-day temporary travel deferral offers an extremely wide margin of safety for the possible transmission of Zika by a donation obtained from someone who recently returned from a country where the virus is circulating.
Publisher: Wiley
Date: 24-12-2022
DOI: 10.1111/TRF.17234
Publisher: Wiley
Date: 10-04-2017
DOI: 10.1111/TRF.14089
Abstract: Hepatitis E virus (HEV) is a virus of emerging importance to transfusion medicine as studies on blood donors and other populations demonstrate that the prevalence of endemic cases is higher than previously recognized and the risk to vulnerable transfusion recipients is not insignificant. We carried out an HEV prevalence study on 13,993 Canadian blood donors with polymerase chain reaction (PCR) testing on all donors and antibody testing on a subset of 4102 donors. HEV antibody-positive and age- and sex-matched antibody-negative donors were invited to participate in a scripted telephone interview about risk factors. There were no PCR-positive s les found (95% confidence interval [CI], 0%-0.026%). The seroprevalence of HEV in our tested population was 5.9% (95% CI, 5.16%-6.59%). HEV antibody positivity was associated with male sex and increasing age. In case-control analysis history of living outside Canada (odds ratio [OR], 2.9 95% CI, 1.56-5.32) and contact with farm animals (OR, 1.5 95% CI, 1.01-2.28) were associated with HEV seropositivity. This is the largest data set to date on HEV infection in Canada. Results suggest low lifetime exposure to HEV and that infectious donations are rare.
Publisher: Wiley
Date: 05-02-2017
DOI: 10.1111/TRF.14001
Abstract: Exposure to blood products during pregnancy carries a potential risk of transfusion transmission of infectious agents. Blood agencies have historically sought optimal deferral and testing strategies to protect blood supplies in part to ensure the protection of pregnant women and their unborn infants. The Zika virus outbreak of 2016 has heightened attention to these concerns. In the current context of the recent Zika outbreak, and also more broadly, data are needed to shed light on the likelihood of exposure to blood products throughout pregnancy to inform policy. Hospital administrative data from a large tertiary care center were examined for outpatient and nondelivery inpatient transfusion events in pregnant women between January 1, 2007, and December 31, 2013. Those pregnancies resulting in miscarriage were excluded from analysis. A total of 45,179 pregnancies resulting in delivery of a live or stillborn infant were documented at The Ottawa Hospital during the study period. Our findings indicate that 0.124%, or 1240 in 1,000,000, expectant mothers received transfusion at some point during their pregnancies with 0.04%, or 400 per 1,000,000, expectant mothers receiving a transfusion in the first trimester. Data from a large tertiary care center suggest that the risk of maternal and fetal exposure to blood products by transfusion during any stage of pregnancy is very low. Such a low likelihood of transfusion should be taken into consideration when developing donor deferral policies designed to protect women against transfusion-associated infection transmission during pregnancy and could inform evaluations of the risk of prenatal transfusion transmission of the Zika virus.
Publisher: Wiley
Date: 20-06-2022
DOI: 10.1111/TME.12888
Abstract: To reduce the risk of HIV transmission through transfusion, gay, bisexual and other men who have sex with men (gbMSM) are deferred from donating blood in many countries for varying lengths of time after having sex with another man. In 2021, screening algorithms to identify high‐risk sexual behaviours using gender‐neutral criteria (i.e., without any question on MSM or time deferral for MSM) were implemented in the United Kingdom based on recommendations in a report from the FAIR (For the Assessment of In idualised Risk) steering group. This study examines the potential donation loss expected with these criteria if implemented in Canada. Responses from blood donors regarding engagement in behaviours such as chemsex and anal sex with a new or multiple partners within 3 months of donation were collected using an on‐site paper questionnaire. Applying the FAIR criteria resulted in donation loss of 1.0% (95% CI: 0.8% – 1.1%). Donation loss would be higher amongst younger donors aged 17–25 (2.0%, 95% CI: 1.6% – 2.3%). Overall, 20% of donors reported feeling uncomfortable answering study questions but only 2.0% said it would stop them from donating. Donation loss could be compensated by newly eligible gbMSM and with increased recruitment and encouraging donation from infrequent donors.
Publisher: Wiley
Date: 02-2010
DOI: 10.1111/J.1423-0410.2009.01236.X
Abstract: In the mid-1980s, confidential unit exclusion (CUE) was implemented to permit donors unwilling to admit risk factors in screening to exclude their donation from transfusion. With changes in donor behaviour, epidemiology of disease and improvements in testing, many blood establishments have stopped using it. We evaluated its benefit in Canada, and reported its utility in predicting transmissible-disease (TD) and high-risk behaviour. TD-positive donations and incident cases between 2004 and 2008 were analyzed in CUE-safe and CUE-unsafe designated donations. An anonymous survey of 40,000 donors asked about CUE use and risk factors. There were 7104 (0.15%) donations designated CUE-unsafe of 4,775,044 donations. Most TD-positive donations were designated CUE-safe (1023/1030, 99.32%) with only seven (0.68%) designated CUE-unsafe. Of 95 incident cases, all were designated CUE-safe including three NAT-yield cases (1 HIV and 2 HCV). In the survey, some donors found the CUE difficult to understand [10.5% (first-time), 3.2% (repeat)], only half thought that the blood would still be tested [48.9% (first-time), 45.9% (repeat)], and about a fifth believed that collection site staff could see their designation. No survey respondents who used the CUE admitted to risk behaviour, but about 1% of donors who designated CUE-safe had high-risk behaviours. The data do not provide any indication of a safety benefit from CUE, but CUE use results in a small but constant loss of apparently safe donations.
Publisher: BMJ
Date: 06-2023
DOI: 10.1136/BMJOPEN-2022-071228
Abstract: To determine the SARS-CoV-2 seroprevalence among school workers within the Greater Vancouver area, British Columbia, Canada, after the first Omicron wave. Cross-sectional study by online questionnaire, with blood serology testing. Three main school districts (Vancouver, Richmond and Delta) in the Vancouver metropolitan area. Active school staff enrolled from January to April 2022, with serology testing between 27 January and 8 April 2022. Seroprevalence estimates were compared with data obtained from Canadian blood donors weighted over the same s ling period, age, sex and postal code distribution. SARS-CoV-2 nucleocapsid antibody testing results adjusted for test sensitivity and specificity, and regional variation across school districts using Bayesian models. Of 1850 school staff enrolled, 65.8% (1214/1845) reported close contact with a COVID-19 case outside the household. Of those close contacts, 51.5% (625/1214) were a student and 54.9% (666/1214) were a coworker. Cumulative incidence of COVID-19 positive testing by self-reported nucleic acid or rapid antigen testing since the beginning of the pandemic was 15.8% (291/1845). In a representative s le of 1620 school staff who completed serology testing (87.6%), the adjusted seroprevalence was 26.5% (95% CrI 23.9% to 29.3%), compared with 32.4% (95% CrI 30.6% to 34.5%) among 7164 blood donors. Despite frequent COVID-19 exposures reported, SARS-CoV-2 seroprevalence among school staff in this setting remained no greater than the community reference group. Results are consistent with the premise that many infections were acquired outside the school setting, even with Omicron.
Publisher: Oxford University Press (OUP)
Date: 26-07-2022
DOI: 10.1093/OFID/OFAC349
Abstract: Nucleocapsid serological assay sensitivity to identify severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among vaccinees and for Omicron cases is unclear. In this prospective study, the Elecsys nucleocapsid assay was 89% sensitive in identifying SARS-CoV-2 infections 14–607 days pre–blood collection. Sensitivity was similar when comparing by vaccination status, and in Omicron (vs pre-Omicron) cases.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-03-2021
Publisher: Wiley
Date: 09-12-2016
DOI: 10.1111/TRF.13956
Abstract: We assessed risk groups for iron deficiency and the feasibility and efficacy of ferritin testing in a large blood center. Donors were informed of possible testing in the predonation p hlet. Plasma ferritin was measured on retention s les (n = 12,595) from representative clinics. Low-ferritin donors (<25 µg/L) were sent a letter and information sheet and not called for 6 months. Ferritin testing was repeated on 25% of donors donor return rate and frequency were monitored. Low-ferritin donors represented 2.9% of first-time and reactivated (no donation in past 12 months) male donors, 32.2% of first-time and reactivated female donors, 41.6% of repeat male donors, and 65.1% of repeat female donors. A mean of 11.7 months after index donation, the return rate was 76% for normal and 58% for low-ferritin donors returning low-ferritin donors had made approximately one fewer donation. Ferritin increased by 16.3 and 12.1 µg/L in male and female low-ferritin donors and decreased by 17 µg/L in male and female normal-ferritin donors. The minimum hemoglobin level will be increased to 130 g/L for male donors and the minimum interdonation interval changed to 84 days (four donations yearly) for female donors based on iron deficiency risk groups. Large-scale ferritin testing was feasible. Donors informed of low-ferritin results had a lower return rate, donated less often, and had an increase in ferritin on return, approximately 1 year after initial testing, compared to donors with normal ferritin results.
Publisher: MDPI AG
Date: 25-10-2022
DOI: 10.3390/V14112336
Abstract: With the emergence of the SARS-CoV-2 Omicron variant in late 2021, Canadian public health case/contact testing was scaled back due to high infection rates with milder symptoms in a highly vaccinated population. We monitored the seroprevalence of SARS-CoV-2 nucleocapsid (anti-N) and spike protein (anti-S) antibodies in blood donors across Canada from September 2021 to June 2022 in 202,123 randomly selected s les. Multivariable logistic regression of anti-N positivity with month, age, sex, racialization, region, material and social deprivation (based on postal code) identified as independent predictors. Piece-wise logistic regression analysed the association between anti-S concentration and month, and anti-N/anti-S positivity. Infection-related seroprevalence (anti-N positive) was 4.38% (95% CI: 3.96, 4.81) in September reaching 50.70% (50.15, 52.16) in June nearly 100% were anti-S positive throughout. Anti-N positivity was associated with younger age, male sex, the Alberta and Prairies regions, greater material deprivation and less social deprivation (p 0.001). Anti-S concentration was high initially (3306 U/mL, IQR 4280 U/mL), increased to (13,659 U/mL, IQR 28,224 U/mL) by June (p 0.001), following the pattern of deployment of the third and fourth vaccine doses and was higher in those that were anti-N positive (p 0.001). Despite already high vaccination-related seroprevalence, infection-related seroprevalence increased dramatically with the emergence of the Omicron SARS-CoV-2 variant.
Publisher: Wiley
Date: 27-11-2019
DOI: 10.1111/VOX.12867
Abstract: In Canada, the deferral for men who have sex with men (MSM) was decreased from a permanent deferral to a 5-year then a 12-month deferral. Current HIV testing can detect an HIV infection in donated blood within 2 weeks of exposure thus, a 12-month deferral may be unnecessarily restrictive. We aimed to estimate the residual risk of HIV if the deferral were further decreased to 3 months. Using a deterministic model with stochastic Monte Carlo simulation, residual risk of HIV was the sum of testing error, assay sensitivity and window-period risks. Data inputs were estimated from donor surveillance, donor surveys and published data. Residual risk was modelled at baseline and using three scenarios: (1) most likely - non-compliance, HIV prevalence and incidence rates of MSM are unchanged (2) optimistic - non-compliance improves by 50% and (3) pessimistic - non-compliance, HIV prevalence and incidence rates of MSM all double. HIV residual risk at baseline was 1 in 36·0 million donations (95% CI 1 in 1 504 907 million, 10·5 million) in the most likely scenario 1 in 34·2 million (1 in 225 534 million, 8·7 million) in the optimistic scenario 1 in 36·0 million (1 in 282 618 million, 9·5 million) in the pessimistic scenario 1 in 16·7 million (1 in 39 469 million, 6·0 million). All confidence intervals overlapped. With very low modelled risk under a 12-month deferral, the additional risk with a 3-month deferral is very low. This is true even with a pessimistic scenario.
Publisher: Wiley
Date: 10-04-2019
DOI: 10.1111/VOX.12743
Publisher: Wiley
Date: 13-12-2017
DOI: 10.1111/VOX.12623
Abstract: We review the history and evolution of blood donor criteria for men who have sex with men (MSM). Deferral policies in many jurisdictions, including Australia, New Zealand, Canada, the United States, Brazil and many western European countries are based on a period of abstinence from MSM, often of 12 months duration. Several countries (Italy, Spain and Portugal) defer donors based on sexual behaviours considered to be at high risk, regardless of whether the partner is same sex or opposite sex. Compliance is a key determinant in the efficacy of any deferral policy. We summarize research themes and strategies discussed at a January 2017 meeting held in Toronto, Canada, to provide an evidence basis for future policy changes.
Publisher: Wiley
Date: 07-03-2011
DOI: 10.1111/J.1537-2995.2011.03078.X
Abstract: Few donor criteria are as contentious as the deferral of men who have had sex with men (MSM). We performed an anonymous donor survey to determine attitudes toward current screening and the feasibility and acceptability of adoption of alternate donor criteria for MSM. Donors who had successfully donated to Canadian Blood Services were randomly mailed an anonymous questionnaire several weeks after donation there were 40,000 donors s led, evenly split between first-time and repeat donors. The response rate was 45.5%. The vast majority of donors found the current screening questions and clinic environment acceptable. Attention to clinic educational materials was poor. A total of 53% felt that the MSM criteria should be changed many were supportive of criteria based on specific behaviors rather than a period of abstinence. Gender-neutral questions such as number of sexual partners would result in deferral of large numbers of donors. Many donors would support a change in MSM deferral policy. Implementation of strategies based on donor attention to additional material would be challenging. Universal use of simple gender-neutral questions would result in very high donor loss and are therefore not an acceptable option. The acceptability and feasibility of various screening approaches should be explored further with both donors and advocacy groups.
Publisher: Wiley
Date: 28-02-2019
DOI: 10.1111/VOX.12744
Publisher: Wiley
Date: 12-11-2012
DOI: 10.1111/J.1537-2995.2012.03950.X
Abstract: Various testing strategies may reduce the risk of Chagas disease transmission in nonendemic, low-prevalence countries. Results of the first year of selective testing of at-risk donors at Canadian Blood Services are reported. Since February 2009, platelets were not produced from at-risk donors. Since May 2010, at-risk donors were tested for Trypanosoma cruzi antibodies. Donors testing positive were interviewed about risk factors, and lookback studies were initiated. There were 7255 at-risk donors of 421,979 donors screened (1.72%). Risk factors were born in Latin America (50.6%), mother or maternal grandmother born in Latin America (28%), and 6 months or more travel history or residence in Latin America (19%). Sixteen (16) at-risk donors had T. cruzi repeat-reactive test results of whom 13 confirmed positive. Eleven of 13 were born in Latin America (nine in Paraguay and two in Argentina), and the other two were born in Canada but had short-term travel history and mothers who had been born in Latin America. Ten of the donors spoke German as their first language (all of those born in Paraguay and one born in Canada). There were 148 previous donations (176 components transfused) evaluated by lookback, of which 28% of recipients could be tested. None were positive. Selective testing has mitigated a small risk to the blood supply with very few false-positive results. Most positive donors were born in a risk country, with a concentration of German-speaking immigrants from Paraguay. Residency or travel alone were not clear risk factors.
Publisher: Wiley
Date: 06-11-2015
DOI: 10.1111/TRF.13383
Abstract: A p-value is a number between 0 and 1 that is extremely useful in interpreting research results. Using comparison of the means of two s les as an ex le, a p-value <0.05 suggests that there is enough evidence to presume a real difference between groups from which the s les were drawn (that the "null hypothesis" can be rejected). We say that the difference between the means is statistically significant. However, it isn't iron clad proof and there is still a chance that there is really no difference. Furthermore, a statistically significant difference may not be clinically significant if it is not enough to appreciably affect patient outcomes. We describe the theory behind p-values and some common errors in interpretation.
Publisher: SAGE Publications
Date: 03-1997
DOI: 10.1177/000456329703400214
Abstract: Drug-resistant epilepsy, characterized by ongoing seizures despite appropriate trials of anti-seizure medications, affects approximately one-third of people with epilepsy. Brain stimulation has recently become available as an alternative treatment option to reduce symptomatic seizures in short and long-term follow-up studies. Several questions remain on how to optimally develop patient-specific treatments and manage therapy over the long term. This review aims to discuss the clinical use and mechanisms of action of Responsive Neural Stimulation and Deep Brain Stimulation in the treatment of epilepsy and highlight recent advances that may both improve outcomes and present new challenges. Finally, a rational approach to device selection is presented based on current mechanistic understanding, clinical evidence, and device features.
Publisher: Wiley
Date: 02-05-2022
DOI: 10.1111/TRF.16896
Abstract: To better balance the safety of the blood supply and the inclusion of men who have sex with men (MSM), further improvements are needed to the risk management strategy employed in the Netherlands to reduce transfusion‐transmissible infections (TTIs). A gender‐neutral in idual risk assessment could provide a solution by determining donor eligibility based on sexual behaviors known to increase the risk of TTIs. Our objective is to estimate the proportion of blood donors that would be deferred by such an assessment, as well as their discomfort answering such questions. Two surveys were distributed in May 2020 to assess sexual behavior in blood donors in the last 4, 6, and 12 months, as well as their discomfort reporting such information. A combination of both surveys measured the extent to which discomfort was associated with reporting sexual behavior. A high‐risk sexual behavior pattern was defined as having had multiple sexual partners and having engaged in anal sex, without consistent condom use. Of all 2177 participating whole blood donors, 0.8% report engaging in high‐risk sexual behaviors over the last 4 months and would therefore be ineligible to donate. When accounting for the additional proportion of donors that reported such questions would stop them from donating, 2.0% and 3.2% of female and male donors, respectively, would be lost. Gender‐neutral eligibility criteria based on high‐risk sexual behaviors may reduce the overall number of eligible donors in the Netherlands, but could make blood donation more accessible to a broader group of donors.
Publisher: Wiley
Date: 27-05-2022
DOI: 10.1111/TRF.16930
Abstract: Canadian Blood Services (CBS) screens donors based on group status (e.g., men who have sex with men, MSM) instead of specific, high‐risk sexual practices (e.g., occurrence of condomless sex). The MSM screening question is embedded in a cluster of questions about stigmatized attributes such as history of imprisonment and illicit substance use. This juxtaposition of the “MSM question” and stigmatized attributes may unintentionally cause blood donors to perceive MSM more negatively. The aim of this research is to determine whether the CBS donor eligibility questionnaire generates negative bias against MSM. A national, randomized online study of 903 CBS donors was conducted. Participants completed either the existing blood donor eligibility questionnaire or a modified donor questionnaire that repositioned the MSM question among neutral questions. After completing the existing or modified questionnaire, bias against MSM was measured using the sexuality implicit association test (IAT) and Modern Homonegativity Scale – Gay Men (MHS‐G). Lastly, participants estimated prevalence rates among MSM of certain stigmatized behaviors. Participants who completed the existing donor eligibility questionnaire more strongly associated gay men with negative attributes on the IAT ( p one‐tailed = .045), suggesting question position generated implicit negative bias toward MSM. Responses to the MHS‐G ( p one‐tailed = .506) and prevalence estimation task ( p = .443) indicated that question order had no significant impact on explicit bias. Positioning the MSM screening question among stigmatizing questions creates implicit negative bias against MSM. Policy makers should be mindful of question positioning when designing donor questionnaires.
Publisher: BMJ
Date: 04-2022
DOI: 10.1136/BMJOPEN-2021-057846
Abstract: Few studies reported COVID-19 cases in schools during the 2020/21 academic year in a setting of uninterrupted in-person schooling. The main objective was to determine the SARS-CoV-2 seroprevalence among school staff in Vancouver public schools. Cumulative incident COVID-19 cases among all students and school staff based on public health data, with an embedded cross-sectional serosurvey among a school staff s le that was compared to period, age, sex and geographical location-weighted data from blood donors. Vancouver School District (British Columbia, Canada) from kindergarten to grade 12. Active school staff enrolled from 3 February to 23 April 2021 with serology testing from 10 February to 15 May 2021. SARS-CoV-2 seroprevalence among school staff, based on spike (S)-based (unvaccinated staff) or N-based serology testing (vaccinated staff). Public health data showed the cumulative incidence of COVID-19 among students attending in-person was 9.8 per 1000 students (n=47 280), and 13 per 1000 among school staff (n=7071). In a representative s le of 1689 school staff, 78.2% had classroom responsibilities, and spent a median of 17.6 hours in class per week (IQR: 5.0–25 hours). Although 21.5% (363/1686) of surveyed staff self-reported close contact with a COVID-19 case outside of their household (16.5% contacts were school-based), 5 cases likely acquired the infection at school based on viral testing. Sensitivity/Specificity-adjusted seroprevalence in 1556/1689 staff (92.1%) was 2.3% (95% CI: 1.6% to 3.2%), comparable to a sex, age, date and residency area-weighted seroprevalence of 2.6% (95% CI: 2.2% to 3.1%) among 5417 blood donors. Seroprevalence among staff was comparable to a reference group of blood donors from the same community. These data show that in-person schooling could be safely maintained during the 2020/21 school year with mitigation measures, in a large school district in Vancouver, Canada.
Publisher: Wiley
Date: 12-12-2022
DOI: 10.1111/VOX.13391
Abstract: Policies regarding medication use vary between blood centres. We evaluated medication use in eligible Canadian Blood Services whole blood donors to inform possible process improvements and allow comparisons between donors and the general population. All donors are asked about medication use in the last 3 days, and medications and their reason for use are documented in our donor computer system. Donor computer records were reviewed from January 1, 2020, to March 31, 2022 to extract information on medications by donor age and sex medications were grouped into therapeutic classes. Stability of medication use over time was determined in a random s le of 100 donors who made at least two donations in the study period. One‐third of successful (eligible) donors were taking medications of these, 80% were on one or two medications. Five classes of medication accounted for 72% of medication use, and 13 classes account for 93% of use. Use remains relatively stable over time. Medication use is common, with a few classes accounting for most use. Drop‐down lists and storage of information from one donation to the next may enhance efficiency.
Publisher: Cold Spring Harbor Laboratory
Date: 04-03-2022
DOI: 10.1101/2022.03.01.482592
Abstract: Emerging evidence indicates that longer SARS-CoV-2 vaccine dosing intervals results in an enhanced immune response. However, the optimal vaccine dosing interval for achieving maximum immunogenicity is unclear. This study included s les from adult paramedics in Canada who received two doses of either BNT162b2 or mRNA-1273 vaccines and provided blood s les 6 months (170 to 190 days) after the first vaccine dose. The main exposure variable was vaccine dosing interval (days), categorized as “ short ” (first quartile), “ moderate ” (second quartile), “ long ” (third quartile), and “ longest” interval (fourth quartile). The primary outcome was total spike antibody concentrations, measured using the Elecsys SARS-CoV-2 total antibody assay. Secondary outcomes included: spike and RBD IgG antibody concentrations, and inhibition of angiotensin-converting enzyme 2 (ACE-2) binding to wild-type spike protein and several different Delta variant spike proteins. We fit a multiple log-linear regression model to investigate the association between vaccine dosing intervals and the antibody concentrations. A total of 564 adult paramedics (mean age 40 years, SD=10) were included. Compared to “short interval” (≤30 days), higher dosing interval quartiles ( moderate : 31-38 days long : 39-73 days and longest : ≥74 days) were all associated with increased Elescys spike total antibody concentration. Compared to the short interval, “ long ” and “ longest ” interval quartiles were associated with higher spike and RBD IgG antibody concentrations. Similarly, increasing dosing intervals increased inhibition of ACE-2 binding to viral spike protein, regardless of the vaccine type. Increased mRNA vaccine dosing intervals longer than 30 days result in higher levels of circulating antibodies and viral neutralization when assessed at 6 months.
Publisher: CMA Impact Inc.
Date: 13-08-2023
DOI: 10.1503/CMAJ.230249
Publisher: American Society for Microbiology
Date: 27-04-2022
DOI: 10.1128/SPECTRUM.00339-22
Abstract: Throughout the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, our blood donor seroprevalence study has informed Canadian public health policy at national and provincial levels. We describe the only continuously running national seroprevalence study in Canada, which spans the full length of the pandemic and per capita is one of the largest programs in the world.
Publisher: Elsevier BV
Date: 07-2015
DOI: 10.1016/J.TMRV.2015.03.004
Abstract: Addressing risk of imported malaria is complicated by 5 human species of Plasmodium, semi-immunity in donors with long-term exposure, increasing travel and immigration, changing risk in endemic areas, and limitations of screening assays. To gain insight into policy formulation, we have compiled epidemiologic data from 5 countries with different policies involving either deferral (the United States and Canada) or selective testing (France, England, and Australia). The greatest risk is from semi-immune former residents of endemic areas, but the greatest impact on sufficiency (donor loss) is from low-risk short-term travel. France and the UK have the highest rates of travel to Africa where most malaria cases originate. The UK has substantial travel to the Indian subcontinent where Plasmodium vivax cases are more common, and Australia, to Southeast Asia and Papua New Guinea. In the United States and Canada, malaria risk travel is more often to lower risk areas such as Mexico and the Caribbean. Each country has imported cases, predominantly Plasmodium falciparum and P. vivax, although data are incomplete. Transfusion-transmitted malaria has been rare over the last 10 years, generally involving P. falciparum, but there were 2 US cases of Plasmodium malariae. Uncertainty due to limitations of epidemiologic data and reliance on donors' answers underpins much of the complexity of policy formulation. Variability in policies between countries reflects not only epidemiologic differences but also operational considerations, donor demographics, regulatory approaches, and public pressure to react to rare transfusion-transmitted malaria cases. Testing reduces the operational impact of addressing the very small risk from travelers and offers improvement over deferral by testing all former residents of endemic areas. Notwithstanding current international regulatory requirements, policies have "evolved" through a series of additions and revisions as concerns and issues arose, with resultant variability in donor selection criteria.
Publisher: Oman Medical Journal
Date: 12-11-2019
DOI: 10.5001/OMJ.2019.92
Publisher: Wiley
Date: 20-04-2021
DOI: 10.1111/TRF.16375
Abstract: There are several strategies to reduce donor reactions. We report donor participation and reaction rates before and after implementing multiple measures at Canadian Blood Services. We introduced a structured program of 500 mL of water and a salty snack pre‐donation and applied muscle tension (AMT) during donation. Donors were not deferred for out of range blood pressure (BP) however, BP was measured in first time donors. Time on the donation chair post‐donation was decreased from 5 to 2 min for repeat donors. We assessed participation rates using our quarterly survey of 10,000 recent donors. We extracted vasovagal reactions with loss of consciousness (LOC) from our operational database and compared pre‐implementation (Oct 12,018‐March 31,2019) and post‐implementation (Oct 12,019‐March 31,2020) periods. Survey response rates varied from 11% to 16%. The percentage of donors who drank the water and ate the salty snack increased from 58% to 82% and 44% to 70% over 4 quarters those performing AMT increased from 24% to 41%. Reactions decreased from 19.07 per 10,000 (744 reactions in 390,123 donations) to 14.04 per 10,000 (537 in 382,382 donations) ( p .0001). No first‐time donors with high BP (n = 684) but 5 with low BP (n = 718) had reactions, CI were very large. Achieving optimal participation was challenging. After implementation of a donor wellness initiative based on best practice, rates of vasovagal reactions with LOC decreased by 25%. A larger dataset is necessary to assess the safety contribution of BP deferrals when other mitigation measures are in place.
Publisher: Infectious Disease and Control Branch (IDPCB) - Public Health Agency of Canada
Date: 06-04-2022
Abstract: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic galvanized blood donor seroprevalence studies, which continue to inform public health policy. We propose that the two Canadian blood suppliers, Héma-Québec and Canadian Blood Services, expand their role in public health surveillance in the post-pandemic period. Together blood suppliers have near-national reach, collecting blood donations nearly every day in all larger cities and many smaller municipalities. Blood donors are a healthy subset of the general population. Demographic data, routine infectious disease testing and screening questionnaire data are collected for all donations. Close to one million blood s les per year could be made available for surveillance. With 90% repeat donors, longitudinal s ling is possible. Current blood donor surveillance includes monitoring infectious marker rates in low risk (e.g. HIV, hepatitis C virus) or asymptomatic (e.g. West Nile virus) populations, and ad hoc studies to monitor transfusion-transmissible infections. These include tick-borne infections such as Babesia microti and foodborne infections such as hepatitis E. Canadian Blood Services and Héma-Québec are actively seeking to engage with public health professionals to further develop a role in public health surveillance.
Publisher: Oxford University Press (OUP)
Date: 12-2012
Publisher: American Society for Microbiology
Date: 14-02-2023
DOI: 10.1128/SPECTRUM.03356-22
Abstract: Canadian blood donors are a healthy adult population that shows clear disparities associated with racialization and material deprivation. This underscores the pervasiveness of the socioeconomic gradient on SARS-CoV-2 infections in Canada.
Publisher: Wiley
Date: 25-04-2013
DOI: 10.1111/TRF.12219
Abstract: Selective testing of donors for Trypanosoma cruzi infection relies on identification of at-risk donors with screening questions. Using risk modeling and a seroprevalence study, we evaluated the risk of questions failing to identify T. cruzi antibody-positive donors. The rate of donors with unreported risk was estimated by a telephone survey of 2677 donors who answered "no" to risk questions. The number of T. cruzi antibody-positive donors missed by risk questions was estimated from the product of this rate and the selective testing T. cruzi antibody-positive rate. The 95% confidence interval (CI) was estimated by Monte Carlo simulation. To test the model, 60,132 donors were tested for T. cruzi antibody (26% of donors in selected regions, Phase I). In Winnipeg, Manitoba, the highest-risk region, 26,915 donors were tested (92.5% of donors, Phase II). In the telephone survey, 21 (0.8%) donors reported risk factors that would have identified them for selective testing. Seven were born in Mexico or Central or South America, five had travel risk, and nine had mother or maternal grandmother risk. The 95% CI for predicted number of T. cruzi antibody-positive donors answering "no" to risk questions was 0.71 to 4.38. In Phase I, one Winnipeg donor confirmed positive but had answered risk questions correctly. No other positive donations were identified. The estimated risk of T. cruzi-positive donors who answer "no" to risk questions is low and is confirmed by the seroprevalence among these donors.
Publisher: Wiley
Date: 20-03-2009
DOI: 10.1111/J.1537-2995.2008.02037.X
Abstract: In August 2005, the Canadian Blood Services decreased the deferral period for tattooing and ear or body piercing from 12 to 6 months. This study assessed the impact of this change on blood safety and availability. The prevalence of these activities was assessed on an anonymous mail-out survey of 40,000 recent donors. Transmissible disease (TD) marker rates were calculated using the National Epidemiology Donor Database. A case-control study was performed comparing risk factors in TD-positive donors with matched controls. Donor deferral rates were assessed before and after the change in deferral period. The prevalence rates of tattoo, ear piercing, and body piercing were 13.7, 53.6, and 10.4 percent in survey respondents, respectively, with up to 0.7 percent of activity likely to represent deferrable risk. TD marker rate was low and stable at 21.6 per 100,000 donations before and 19.2 per 100,000 donations after the change in deferral length. Remote tattoo was associated with hepatitis C virus (HCV) risk (odds ratio, 5.43 95% confidence interval, 1.82-16.2), but neither recent tattoo nor piercing was a risk factor for HCV or hepatitis B virus. Shortening of the deferral period reduced deferrals by 20 percent for tattoo and 32 percent for piercing. There was no measurable adverse effect on safety and a positive but less than expected effect on blood availability after shortening the deferral period for tattoo and piercing. The length of other temporary deferrals should be reassessed, since their current contribution to blood safety may be negligible.
Publisher: AME Publishing Company
Date: 06-2020
Publisher: American Diabetes Association
Date: 12-1995
DOI: 10.2337/DIACARE.18.12.1602
Abstract: To determine the association between exercise-induced albuminuria and the development of microalbuminuria over 10 years in subjects with insulin-dependent diabetes mellitus (IDDM) who were initially normoalbuminuric. Thirty-two patients with IDDM and a resting urinary albumin/creatinine ratio (UA/UC) & .1 mg/mmol (& 15 μg/min) were exercised after water loading on a treadmill for 20 min at double their resting heart rate. UA/UC was determined before and after exercise. The exercise test was considered positive if the UA/UC was & .3 mg/mmol (& μg/min). Results were compared with resting UA/UC after a 10-year follow-up. Persistent microalbuminuria was defined as a UA/UC & .1 mg/mmol (& 15 μg/min) in each of two early-morning urine collections. Five patients developed persistent microalbuminuria after 10 years, and four patients were predicted by a positive exercise test. Two patients with positive exercise tests did not develop persistent microalbuminuria. The sensitivity of the exercise test for the development of microalbuminuria was 80% (95% confidence interval [CI] 65.8–94.2%) and the specificity was 92.9% (95% CI 83.9–100%). The postexercise UA/UC was positively associated with the UA/UC after 10 years (P = 0.005, R2 = 0.31). This association was independent of HbA1, systolic blood pressure, body mass index, and duration of diabetes, but HbA1 remained an independent predictor (P = 0.02) of UA/UC at follow-up. Exercise testing may be useful for identifying normoalbuminuric IDDM patients who are susceptible to the later development of microalbuminuria.
Publisher: Wiley
Date: 15-03-2023
DOI: 10.1111/VOX.13424
Publisher: Wiley
Date: 28-07-2006
DOI: 10.1111/J.1537-2995.2006.00906.X
Abstract: Predonation screening has become more elaborate over the years, while human immunodeficiency virus (HIV)- and hepatitis C virus (HCV)-positive donations have declined. The impact of face-to-face interviewing and of the format of the Donor Health Assessment Questionnaire (DHAQ) have not been evaluated. Canadian Blood Services DHAQ records between 1990 and 2004 were examined, and changes in them were tracked. The proportion of first-time donors permanently deferred for HIV or HCV risk, and the HIV and HCV rates per 100,000 donations, were calculated annually. Time-series analysis was used to determine whether major predonation screening changes had any effect on the HIV or HCV rates or permanent deferrals. In 1992, receiving money or drugs for sex was added to the DHAQ otherwise, the content of high-risk questions changed little between 1990 and 2004. In 1997, the method of administration of the DHAQ changed from donor-completed to face-to-face interviewing for high-risk questions. Permanent deferrals for HIV or HCV risk factors and HIV and HCV rates in first-time donors decreased over this period. The HIV rates were close to 0 before 1997, whereas HCV rates decreased steadily through 2004. There was no interruption in rates in 1997 when the method of administration changed. Face-to-face interviewing for high-risk questions had no effect on HIV or HCV rates in first-time donations over 15 years of observation (during the latter 8 of which face-to-face interviewing was in place), and it did not increase permanent deferrals for HIV or HCV risk factors.
Publisher: Wiley
Date: 05-02-2008
DOI: 10.1111/J.1423-0410.2007.01034.X
Abstract: Predonation screening questions about sexual risk factors should provide an extra layer of safety from recently acquired infections that may be too early to be detected by testing. Donors are required to read a definition of sex as it applies to predonation screening questions each time they come to donate, but how well donors apply such definitions has not been evaluated. We aimed to determine how donors define sex when answering screening questions. In total, 1297 whole blood donors were asked in a private interview to select from a list of sexual activities which ones they believed were being asked about in sexual background questions. Donors' definitions were coded as under-inclusive, correct or over-inclusive in relation to the blood services' definition. Qualitative interviews were carried out with 21 donors to understand reasoning behind definitions. Most donors had an over-inclusive definition (58.7%) or the correct definition (31.9%). Of the 9.4% of donors who had an under-inclusive definition, 95% included both vaginal and anal sex, but not oral sex. About 9% in each group were first-time donors (P > 0.05) who had never read the definition. The qualitative interviews indicated that donors reason their definition based on their own concept of transmissible disease risk. Donors apply a range of definitions of sex when answering questions about their sexual background. This may be due to different concepts of risk activities, and required reading of the definition has little impact.
Publisher: Wiley
Date: 14-05-2015
DOI: 10.1111/VOX.12298
Abstract: Mandatory predonation reading materials inform donors about risk factors for transmissible disease, possible complications of donation and changes to the donation process. We aimed to assess the attention to predonation reading materials and factors which may affect attention. A national survey in 2008 of 18,108 blood donors asked about self-assessed attention to reading the materials. In face-to-face interviews, 441 donors completed additional questions about reading the materials and a literacy test. Qualitative interviews of 27 donors assessed their approach to reading. In the national survey, most of the first-time donors said they read all or most of the materials (90.9% first-time vs. 57.6% repeat donors, P < 0.001) and 66% vs. 23.1% reported reading them carefully (P 0.05), but fewer recalled seeing the definition of sex (77.2%, 56.9, 24.2 P 0.05). Qualitative interviews showed that donors are reluctant to read any more than necessary and decide based on perceived importance or relevance. Attention to predonation reading materials tends to be better among first-time donors. The effectiveness is limited by low motivation to read, especially for repeat donors, as well as poor literacy.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.RESUSCITATION.2019.10.016
Abstract: The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research.
Publisher: Wiley
Date: 06-02-2019
DOI: 10.1111/TRF.15155
Abstract: To reduce donor iron deficiency in whole blood donors, we changed our hemoglobin (Hb) cutoff in males and interdonation interval in females. A change in messaging to females in fall 2016 was followed by changing the interdonation interval from 56 to 84 days in the appointment booking system (December 2016) and actual donation criterion (March 2017). The minimum Hb for males increased from 125 g/L to 130 g/L (March 2017). We evaluated Hb levels and deferral rates, donor presentations with a Hb level below 120 g/L, donation frequency, and donor base size before and after these changes. The Hb deferral rate decreased in females from 13.0% to 9.5%, increased in males from 1.2% to 2.1%, and decreased overall from 6.8% to 5.4% (all p < 0.001). Mean Hb increased from 135.0 g/L to 136.2 g/L in females and from 149.9 g/L to 150.6 g/L in males (both p < 0.0001). The percentage of presentations with Hb below 120 g/L decreased by 27% in males and females (p < 0.001). Annual donation frequency decreased by 12% in females and 4% in males the donor base was expanded by 5.8%. Many positive impacts were seen for female donors, including a shift in the Hb distribution curve to the right, and a large reduction in Hb deferrals. For males, there was an increase in Hb deferrals and a small increase in mean Hb. Changes were related to both reduced donation frequency and a shift in composition of the donor base.
Publisher: BMJ
Date: 08-2021
DOI: 10.1136/BMJOPEN-2021-052282
Abstract: The COVID-19 pandemic has an excessive impact on residents in long-term care facilities (LTCF), causing high morbidity and mortality. Early detection of presymptomatic and asymptomatic COVID-19 cases supports the timely implementation of effective outbreak control measures but repetitive screening of residents and staff incurs costs and discomfort. Administration of vaccines is key to controlling the pandemic but the robustness and longevity of the antibody response, correlation of neutralising antibodies with commercial antibody assays, and the efficacy of current vaccines for emerging COVID-19 variants require further study. We propose to monitor SARS-CoV-2 in site-specific sewage as an early warning system for COVID-19 in LTCF and to study the immune response of the staff and residents in LTCF to COVID-19 vaccines. The study includes two parts: (1) detection and quantification of SARS-CoV-2 in LTCF site-specific sewage s les using a molecular assay followed by notification of Public Health within 24 hours as an early warning system for appropriate outbreak investigation and control measures and cost–benefit analyses of the system and (2) testing for SARS-CoV-2 antibodies among staff and residents in LTCF at various time points before and after COVID-19 vaccination using commercial assays and neutralising antibody testing performed at a reference laboratory. Ethics approval was obtained from the University of Alberta Health Research Ethics Board with considerations to minimise risk and discomforts for the participants. Early recognition of a COVID-19 case in an LTCF might prevent further transmission in residents and staff. There was no direct benefit identified to the participants of the immunity study. Anticipated dissemination of information includes a summary report to the immunity study participants, sharing of study data with the scientific community through the Canadian COVID-19 Immunity Task Force, and prompt dissemination of study results in meeting abstracts and manuscripts in peer-reviewed journals.
Publisher: Wiley
Date: 15-01-2008
DOI: 10.1111/J.1537-2995.2007.01618.X
Abstract: Hepatitis C virus (HCV) rates have decreased steadily in first-time donors in Canada since testing was implemented but reasons are unclear. A description of factors that may have played a role in this decline is reported. Descriptive analysis of first-time blood donors by HCV positivity status and year (1993--2006), sex, and age was carried out. HCV-positive first-time donors and matched controls participated in a confidential scripted telephone interview about risk factors in 1993 through 1994 and in 2005 through 2006, and risk factors independently predicting HCV positivity were determined with multiple logistic regression. HCV-positive donations occurred most frequently in donors born between 1945 and 1964 and decreased in this birth cohort over time (p < 0.01). At present, most first-time donors (74%) are born after 1964. History of intravenous drug use, sex with an intravenous drug user, blood transfusion, and tattoo independently predicted (p < 0.01) HCV positivity in both periods (1993--1994 and 2005--2006). Most HCV-positive donors were born between 1945 and 1964, and the decline in HCV rates is associated primarily with this birth cohort. The key risk factors predicting HCV positivity did not change over the 13 years of the study. With approximately two-thirds of HCV-positive Canadians in the general population having been tested for HCV, potential donors may be aware of their HCV status and be likely to self-defer. This, and an increasing proportion of first-time donors born after 1964, may contribute to declining HCV rates in first-time donors.
Publisher: American Society for Microbiology
Date: 29-06-2022
DOI: 10.1128/SPECTRUM.01134-22
Abstract: We describe the qualitative test characteristics of the Abbott SARS-CoV-2 IgG II Quant assay against four other anti-SARS-CoV-2 IgG assays commonly used in Canada. Although there is no gold standard for identifying anti-SARS-CoV-2 seropositivity, aggregate standards can be used to assess seropositivity.
Publisher: American Society for Microbiology
Date: 17-08-2023
DOI: 10.1128/SPECTRUM.05256-22
Abstract: SARS-CoV-2 Omicron emergence occurred in Canada during the period from November 2021 to January 2022. This study assessed the ability of donor plasma collected earlier (January to March 2021) to generate any neutralizing capacity against Omicron BA.1 SARS-CoV-2.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2016
Publisher: Wiley
Date: 10-03-0002
Publisher: Wiley
Date: 06-12-2018
DOI: 10.1111/VOX.12727
Abstract: Globally, blood safety interventions have been successful in mitigating risk of the major transfusion-transmitted (TT) viruses. However, strategies that address risk from parasites are comparatively limited. TT parasites are often regional in nature, posing unique challenges we sought to understand their impact on blood safety. An electronic questionnaire was distributed to transfusion medicine leaders in 100 countries. The survey focused on specific questions pertaining to four parasitic diseases: babesiosis, Chagas, leishmaniasis and malaria. Respondents provided data on historical TT cases, local epidemiology, policies to mitigate risk and an assessment of public health perceptions for each aetiologic agent. Twenty-eight (28%) surveys were returned from countries in Europe (n = 13), the Americas (n = 6), Africa (n = 4), Asia (n = 3) and Oceana (n = 2). Historically, no cases of TT leishmaniasis were reported, TT babesiosis was exclusive to Canada and the USA, TT Chagas was limited to the Americas and Spain, while TT malaria was cosmopolitan. Mitigation efforts varied widely malaria was the most frequently tested parasitic disease. The public's perception of risk for parasitic agents was low, while that of health authorities in endemic countries was higher. The global impact of parasitic infections on blood safety and related mitigation efforts varied widely by parasite epidemiology, test availability, public health priorities and socioeconomic constraints. While parasites continue to pose a risk to blood safety, the successful mitigation of viral risk has elevated the prominence of TT parasites in many locations, thereby requiring consideration of mitigation efforts.
Publisher: Elsevier BV
Date: 07-2007
DOI: 10.1016/J.TMRV.2007.03.002
Abstract: Over the last 20 years, the Canadian Blood Services' (CBS) Donor Health Assessment Questionnaire (DHAQ), used to screen prospective blood donors to determine their eligibility, has grown in complexity and length. Its growth is inextricably linked to the evolution of the environment within which CBS operates from unregulated collection and distribution of labile blood products to a fully regulated environment and to the need to satisfy both Health Canada and US Food and Drug Administration (FDA) requirements. Within this context, the development of the CBS DHAQ has been characterized by addition of questions and items without any periodic reevaluation of the need for retaining existing questions and/or items. In this review, we apply principles from cognitive science relating to how people think when answering questionnaires to the situation of blood donors completing the DHAQ. We show that some items that were added at different times in separate questions, for reasons that were historically relevant, could be now asked more simply with a single question. The historical development of the DHAQ, resulting in the condensing of many items into lists, the use of complex wording, and the sheer number of items included in the questionnaire make accurate retrieval of information from the donor's memory difficult. Thus, we believe that redesigning the DHAQ will improve the quality and accuracy of the donors' answers to screening questions.
Publisher: Wiley
Date: 23-09-2012
DOI: 10.1111/J.1365-3148.2012.01184.X
Abstract: Using population prevalence data for deferrable diseases/conditions we estimated the Canadian population eligible to donate according to three upper-age limit scenarios. The donor selection criteria limit the number of potential blood donors but relaxing the upper age criteria could mitigate this. Forty deferral criteria were identified and their corresponding prevalence data obtained to estimate the number of people excluded by the criteria. The eligible blood donor population was estimated from national census data taking the age limits, deferral criteria and deferral time-period into account. As more than one disease/condition may co-exist, the estimate was adjusted to avoid over-representation. Of about 33 million Canadians aged 17 (18 in Québec) to 65, 15·1 million (45·8%) are eligible to donate blood. This number increases to 15·7 million when including people up to 71 years and to 17·1 million in the absence of an upper age limit. As about 1·2 million units are collected from 600,000 donors annually, there are more than enough eligible people to meet the need. However, recruitment of donors is challenging and the absence of an upper age limit allows an additional 2 million people to donate. Other countries may wish to consider modification of the upper age criterion to address the effect of an aging population on the blood supply.
Publisher: Wiley
Date: 06-1996
DOI: 10.1002/(SICI)1096-9136(199606)13:6<520::AID-DIA128>3.0.CO;2-D
Abstract: To identify Coronavirus disease (COVID-19) cases efficiently, affordably, and at scale, recent work has shown how audio (including cough, breathing and voice) based approaches can be used for testing. However, there is a lack of exploration of how biases and methodological decisions impact these tools' performance in practice. In this paper, we explore the realistic performance of audio-based digital testing of COVID-19. To investigate this, we collected a large crowdsourced respiratory audio dataset through a mobile app, alongside symptoms and COVID-19 test results. Within the collected dataset, we selected 5240 s les from 2478 English-speaking participants and split them into participant-independent sets for model development and validation. In addition to controlling the language, we also balanced demographics for model training to avoid potential acoustic bias. We used these audio s les to construct an audio-based COVID-19 prediction model. The unbiased model took features extracted from breathing, coughs and voice signals as predictors and yielded an AUC-ROC of 0.71 (95% CI: 0.65-0.77). We further explored several scenarios with different types of unbalanced data distributions to demonstrate how biases and participant splits affect the performance. With these different, but less appropriate, evaluation strategies, the performance could be overestimated, reaching an AUC up to 0.90 (95% CI: 0.85-0.95) in some circumstances. We found that an unrealistic experimental setting can result in misleading, sometimes over-optimistic, performance. Instead, we reported complete and reliable results on crowd-sourced data, which would allow medical professionals and policy makers to accurately assess the value of this technology and facilitate its deployment.
Publisher: Wiley
Date: 09-03-2023
DOI: 10.1111/VOX.13419
Abstract: The distribution of rare and specific red cell phenotypes varies between races and ethnicities. Therefore, the most compatible red cell units for patients with haemoglobinopathies and other rare blood requirements are most likely to be found in donors from similar genetic backgrounds. Our blood service introduced a voluntary question asking donors to provide their racial background/ethnicity. Results triggered additional phenotyping and/or genotyping. We analysed the results of additional testing performed between January 2021 and June 2022, and rare donors were added to the Rare Blood Donor database. We determined the incidence of various rare phenotypes and blood group alleles based on donor race/ethnicity. Over 95% of donors answered the voluntary question 715 s les were tested, and 25 donors were added to the Rare Blood Donor database, including five k−, four U−, two Jk(a−b−) and two D− − phenotypes. Asking donors about their race/ethnicity was well received by donors, and the resulting selective testing enabled us to identify in iduals with a higher likelihood of being rare blood donors, support patients with rare blood requirements and better understand the incidence of common and rare alleles and red blood cell phenotypes in the Canadian donor population.
Publisher: Wiley
Date: 22-01-2007
DOI: 10.1111/J.1537-2995.2007.01108.X
Abstract: New testing methods such as nucleic acid lification testing (NAT) and chemiluminescent serologic assays have been introduced, more precise estimates for infectious window periods are available, and a new method for estimating the residual risk (RR) of transfusion-transmitted infections (TTIs) has been developed. Thus, available RR estimates for Canada need to be updated. Incidence rates for known TTI markers were determined for all allogeneic whole-blood donations made to Canadian Blood Services between 2001 and 2005 they were derived from NAT conversions or seroconversions of repeat donors with at least two donations in a 3-year period. RR estimates for human immunodeficiency virus (HIV)-1 and hepatitis C virus (HCV) derived from the classical incidence/window-period model were compared to those obtained by the new method that estimates incidence from NAT-positive, antibody-negative donations (NAT-yield cases) from all donors ided by person-years. With the classical method, the RR of HIV (1 per 7.8 million donations) and HCV (1 per 2.3 million) were low HBV RR was higher (1 per 153,000). HCV RR was significantly lower when estimated with the new method (1 per 13 million). Eleven HCV NAT-yield cases were predicted by applying the classical method to our seroconversion data but only 2 were observed (p = 0.011). Observed HIV-1 NAT-yield cases (n = 1) matched those predicted (n = 0.7). New tests have reduced an already low risk of TTI in Canada. HCV RR estimates by two different methods differed but both were low.
Publisher: Wiley
Date: 26-01-2006
DOI: 10.1111/J.1537-2995.2006.00744.X
Abstract: Predonation screening questions about travel increase the safety of the blood supply from diseases such as variant Creutzfeldt-Jakob disease (vCJD) and malaria. This study examines the ability of sequential surveys to predict actual travel deferrals and the operational validity of travel questions. To assess donor travel histories before implementing key deferral policies, two donor surveys were carried out at Canadian Blood Services collection sites in February 1999 (8026 donors) and March 2001 (13,623 donors). In-person interviews were carried out with 1530 donors to assess the operational validity of the short travel question. Time-series analysis was used to determine whether there was a change in deferrals when deferral policies were implemented. Predicted donor loss estimates based on survey results were compared with actual deferrals. Deferrals increased significantly (p < 0.05) when vCJD deferral policies were implemented in October 1999 and September 2001, but not in October 2000. Survey data accurately predicted deferrals 6 months after implementation from the initial policy (2.51% predicted vs. 2.51% actual), but there were fewer deferrals than predicted for the second (2.89% predicted vs. 2.26% actual, p < 0.01) and third deferral policies (3.10% predicted vs. 1.89% actual, p < 0.01). There was 96 percent agreement between donor responses to a short screening question and a detailed travel history. The initial survey accurately predicted the actual donor deferral rate, but the deferral rate was less than predicted for subsequent, more stringent donor deferral policies. Donors answered a short travel question suitable for donor screening similarly to a very detailed travel history.
Publisher: Wiley
Date: 06-2001
Publisher: Wiley
Date: 11-2018
DOI: 10.1111/VOX.12722
Abstract: In Canada, transfusion transmission risk of Human T-cell lymphotropic virus -I/II (HTLV) is addressed by universal leucoreduction and universal antibody testing. We aimed to estimate the risk with the current policy, if testing only first-time donors and if testing were stopped. Monte Carlo simulation was employed to estimate the proportion of red cell concentrate, random donor platelet and apheresis platelet units that would be released into inventory in each scenario (10 billion donors each). The model estimated the number of HTLV-positive donations not intercepted by testing, randomly assigned the number of HTLV particles/100 leucocytes using proportions from published data and randomly selected a postleucoreduction leucocyte count from quality control data. Units were considered infectious if ≥9 × 10 With universal leucoreduction in place, the residual risk of releasing an HTLV potentially infectious unit with universal testing was 1 in 1·2 billion units (0, 1 in 55·9 million), with testing only first-time donors 1 in 7·1 million (0, 1 in 1·05 million) and with no testing 1 in 1·0 million (0, 1 in 178 600). The efficacy of leucoreduction was >99·5% (lower bound 95·7%) for all scenarios. With universal leucoreduction in place, switching from universal testing to testing first-time donors would incur very low risk.
Publisher: Cold Spring Harbor Laboratory
Date: 18-06-2021
DOI: 10.1101/2021.06.16.21258861
Abstract: Contact-tracing studies suggest minimal secondary transmission in schools. However, there are limited school data accounting for asymptomatic cases, particularly late in the 2020/21 school year, and in the context of uninterrupted in-person schooling and widespread community transmission. To determine the SARS-CoV-2 seroprevalence in a s le of school staff, compared to the community, and to COVID-19 rates among all students and staff within the same school population. Incident COVID-19 cases among students and school staff using public health data, with an embedded cross-sectional serosurvey among school staff s led from February 10 to May 15, 2021, comparing to age, sex and geographic location-matched blood donors s led in January 2021. Vancouver School District (British Columbia, Canada) from kindergarten to grade 12. Active s chool staff enrolled from February 3 to April 23, 2021. SARS-CoV-2 antibodies in a s le of school staff using spike (S)-based testing (unvaccinated staff) or N-based serology testing (vaccinated staff). The incidence of COVID-19 cases among students attending in-person was 9.8 per 1,000 students during the 2020/21 school year (N = 47,280 students), and among staff was 13 per 1,000 since the beginning of the pandemic (N = 7,071 active school staff). In total, 1,689 school staff (64% elementary, 28% secondary, 8.3% school board staff or multiple grades) completed the questionnaire, 78.2% had classroom responsibilities, and spent a median of 17.6 hours in class per week [IQR: 5.0 – 25 hours]. Although 21.5% (363/1,686) reported close contact with a COVID-19 case, only 1.4% (24/1688) of the school staff reported having had a positive viral nucleic acid test. Of this group, five believed they acquired the infection at school. The adjusted seroprevalence in staff who gave blood (1,556/1,689, 92.1%) was 2.3% [95%CI: 1.6 – 3.2%] compared to 2.3% [95%CI: 1.7 – 3.0%] in blood donors. Despite high reported COVID-19 cases among students and staff, and frequent within-school exposures, we found no detectable increase in seroprevalence among school staff above the community seroprevalence. These findings corroborate claims that, with appropriate mitigation strategies, in-person schooling is not associated with significantly increased risk for school staff. What was the prevalence of COVID-19 infections in school staff who maintained in-person schooling during the 2020/21 school year in Vancouver, British Columbia, and how does it compare to the risk of COVID-19 infection in the community. As of March 4, 2021, the incidence of COVID-19 cases among school staff was 13 per 1,000 (N = 7,071 school staff) since the beginning of the pandemic. In a cross-sectional seroprevalence analysis from February 10 to May 15, 2021, the adjusted seroprevalence among a s le of school staff (N = 1,556) was 2.3% [95%CI: 1.6 – 3.2%], compared to 2.3% [95%CI: 1.7 – 3.0%] in 1:2 age, sex and geographical location (by postal code)-matched reference group of blood donors. We found no detectable increase in seroprevalence among school staff above the community seroprevalence. These findings corroborate claims that, with appropriate mitigation strategies in place, in-person schooling is not associated with significantly higher risk for school staff.
Publisher: MDPI AG
Date: 02-2023
DOI: 10.3390/V15020409
Abstract: Hepatitis B surveillance is essential to achieving Canada’s goal of eliminating hepatitis B by 2030. Hepatitis B rates, association of infection with vaccine age-eligibility, and risk factors were analyzed among 1,401,603 first-time Canadian blood donors from 2005 to 2020. Donors were classified as having likely chronic or likely resolved/occult infections based on hepatitis B surface antigen, anti-hepatitis B core antigen, and hepatitis B nucleic acid test results. Likely chronically infected and control donors (ratio 1:4) participated in risk-factor interviews. The 2019 rate of likely chronic infection was 61.9 per 100,000 (95% CI 46.5–80.86) and 1449.5 per 100,000 for likely resolved/occult infections (95% CI 1370.7–1531.7). Likely chronic infections were higher in males (OR 3.2 95% CI 2.7–3.7) and the vaccine-ineligible birth cohort (OR 1.9 95% CI 1.6–2.2). The main risk factors were living with someone who had hepatitis (OR 12.5 95% CI 5.2–30.0) and ethnic origin from a high-prevalence country (OR 8.4 95% CI 5.9–11.9). Undiagnosed chronic hepatitis B may be more prevalent in Canada than currently determined by traditional passive hepatitis B reporting. Blood donor data can be useful in informing hepatitis B rates and evaluating vaccination programs in Canada.
Publisher: Wiley
Date: 25-11-2022
DOI: 10.1111/VOX.13378
Abstract: In March 2020, the WHO declared the SARS‐CoV‐2 corona virus a pandemic which caused a great disruption to global society and had a pronounced effect on the worldwide supply of blood. In 2022 an on‐line meeting was organised with experts from Austria, Canada, Germany, Greece, Netherlands and United States to explore the opportunities for increasing preparedness within blood systems for a potential future pandemic with similar, or more devastating, consequences. The main themes included the value of preparedness, current risks to the blood supply, supply chain vulnerabilities, and the role of innovation in increasing resiliency and safety. Seven key recommendations were formulated and including required actions at different levels. Although SARS‐CoV‐2 might be seen as a unique event, global health risks are expected to increase and will affect blood transfusion medicine if no preparedness plans are developed.
Publisher: Wiley
Date: 18-07-2023
DOI: 10.1111/VOX.13493
Abstract: No transfusion‐associated cases of variant Creutzfeldt–Jakob disease (vCJD) have occurred in more than 20 years. Yet, many countries have maintained blood donor deferral criteria for vCJD. We developed a risk simulation model to reassess the need for vCJD‐related deferral criteria in Canada. The model provides results separately for Héma‐Québec (HQ) and Canadian Blood Services (CBS). The model used a Monte Carlo simulation approach to estimate the risk of having a vCJD‐contaminated blood donation (‘risk of vCJD’) in a simulated cohort of 10 million donors followed for up to 85 years. The model assumed current deferral criteria for vCJD were lifted, which would allow new ‘at‐risk’ donors to give blood. The model accounted for disease prevalence, donors' travel/immigration history, PRNP genotype at codon 129, demographics and the type of labile blood product. In the base case, the risk of vCJD was estimated at zero at both blood services. In the most pessimistic scenario, the risk of vCJD was 6.4 × 10 −9 (i.e., 1 in 157 million donations) at HQ, or ≤1 in 77 million based on the upper bound of the 95% confidence interval (CI). At CBS, this risk was 4.8 × 10 −8 (i.e., 1 in 21 million donations), or ≤1 in 16 million based on the upper bound of the 95% CI. vCJD poses minimal risks to the Canadian blood supply. Current vCJD deferral criteria may, therefore, be lifted with virtually no impact on safety, while significantly expanding the donor base.
Publisher: Wiley
Date: 12-2021
DOI: 10.1111/TRF.16753
Abstract: In Canada, the deferral for men who have sex with men (MSM) has been progressively reduced from a permanent deferral for MSM since 1977, to 5 years, 1 year, and, most recently, 3 months. We estimated human immunodeficiency virus (HIV) residual risk and compliance with the MSM time deferral after each change. Four anonymous online compliance surveys were carried out before and after each change. HIV incidence and prevalence were monitored from 2010 to 2021. Residual risk was estimated using the incidence‐window period model. Human immunodeficiency virus prevalence, incidence, and residual risk did not change with incrementally shorter MSM deferrals. The residual risk per million donations post 3‐month deferral was 0.05 (0.001–0.371). Men with temporally remote MSM history became eligible and, therefore, compliant as the deferral periods decreased (Cochran‐Armitage p value = .0001). However, the percentage of men with MSM history in the last 3 months with the indefinite deferral in place was similar to the percentage noncompliant, while the 3‐month deferral was in place. MSM donors did not report high‐risk behaviors for which they would otherwise be deferred in any survey. Following the change, an estimated 4467 MSM per year were eligible to donate, an increase from 2501 estimated eligible MSM donors following the change to the 1‐year deferral. With progressively shorter MSM deferral periods, HIV residual risk was unchanged. The proportion of male donors with deferrable MSM history remained low, while those with temporally remote MSM history became eligible, increasing the number of eligible MSM donors.
Publisher: Wiley
Date: 10-11-2022
DOI: 10.1111/VOX.13374
Abstract: The COVID‐19 pandemic has brought to the fore how blood services can partner with public health (PH) authorities to inform decisions. Yet the scope of partnerships between blood services and PH authorities is inadequately documented. We explored how blood services partner with PH authorities outside the scope of COVID‐19. On 19 January 2022, survey was sent to employees of blood services located throughout the world. Survey questions mainly pertained to partnerships with PH authorities, including how blood specimens are used and collected. Twenty‐seven recipients—4 (14.8%) in Africa, 3 (11.1%) in Asia, 9 (33.3%) in Europe, 6 (22.2%) in North America, 2 (7.4%) in Oceania and 3 (11.1%) in South America—completed the survey. Fifteen recipients (55.6%) indicated their blood service was directly or indirectly supervised by PH authorities. Twenty‐four recipients (88.9%) indicated currently using or planning to use blood donor data or s les for PH research or pathogen surveillance. A substantial proportion of respondents reported using s les or results from non‐routine tests for the surveillance of non‐transfusion‐transmitted infectious disease pathogens ( n = 13 [48.1%]) s les or results of non‐routine tests for PH research unrelated to pathogens ( n = 10 [37.0%]) donor data for PH research unrelated to pathogens ( n = 12 [44.4%]) and donor data for PH research unrelated to transfusion safety ( n = 11 [40.7%]). Fourteen (51.9%) had established (or planned to establish) longitudinal cohorts and 19 (70.4%) biobanks. The majority of responding blood services were already involved in or planned to be involved in PH research or pathogen surveillance.
Publisher: Elsevier BV
Date: 04-1996
DOI: 10.1016/0168-8227(96)01252-1
Abstract: We aimed to examine the relationship of serum lipids, lipoproteins, apolipoproteins and antioxidants with renal dysfunction as measured by urinary excretion of albumin and of retinol binding protein (RBP) in insulin-dependent diabetes mellitus (IDDM). We studied 121 patients with IDDM. Glomerular function was assessed as the urinary albumin/creatinine ratio (UA/UC), and tubular function as the urinary retinol-binding protein/creatinine ratio (UR/UC), both measured in three early morning spot urine s les. The mean (range) UA/UC was 1.95 mg/mmol (0.3-476.5) and UR/UC was 17.5 micrograms/mmol (1.0-1853.8). 17% of the patients had a UA/UC > 3 mg/mmol and 33% had a UR/UC > 20 micrograms/mmol. Significant positive correlations were observed between both UA/UC and UR/UC and the following: serum total cholesterol (P < 0.005) triglycerides (P < 0.001) apolipoproteins A-I (P < 0.05), A-II (P < 0.02) and B (P < 0.002) glycated haemoglobin (P < 0.002). No significant associations were found with serum vitamin E, beta-carotene or total antioxidant activity. In multiple regression, only UA/UC was independently associated with serum apo B and cholesterol concentrations. In conclusion, in IDDM glomerular dysfunction, as measured by UA/UC, is associated with elevated serum cholesterol, triglycerides, apo B, apo A-I and apo A-II, but not with HDL cholesterol or antioxidant status. Tubular dysfunction tends to occur with increasing albuminuria, but it is not independently associated with serum lipid, lipoprotein, apolipoprotein or antioxidant levels.
Publisher: Wiley
Date: 19-10-2022
DOI: 10.1111/VOX.13370
Abstract: Donor criteria for diabetes vary significantly. We describe our evolving policies for donors with diabetes, their contribution to the Canadian blood supply and their rate of syncopal reactions compared to other donors. All donors are asked if they have diabetes and have taken medications in the last 3 days. We assessed donors with diabetes on various medications, the number deferred over time, and syncopal reactions in donors with diabetes and other donors in our donor reaction database. Policy changes allowing type 2 diabetic donors on oral hypoglycaemics alone, type 2 diabetic donors on oral medications and insulin and type 1 diabetic donors (all on insulin) to donate resulted in a decrease in deferrals from 450 to 22 donors annually. Of donors being treated with medication for diabetes, 11% are receiving insulin as part of their treatment. Syncopal reaction rates were low and not statistically different between diabetic and non‐diabetic donors, although confidence intervals (CIs) are large. Policies decreased deferrals while maintaining safety. A longer observation period would strengthen these observations.
Publisher: Cureus, Inc.
Date: 31-01-2023
DOI: 10.7759/CUREUS.34465
Publisher: Elsevier BV
Date: 2012
Publisher: Elsevier BV
Date: 04-2020
DOI: 10.1016/J.TMRV.2019.11.007
Abstract: Iron deficiency is a global problem in women of child-bearing age and is associated with adverse maternal and newborn outcomes. Repeated blood donations deplete iron stores and decrease hemoglobin levels. However, the clinical impact of iatrogenic iron deficiency on mothers and neonates due to blood donation is uncertain. The objective of this study was to assess the association between repeated blood donations in female donors of child-bearing age and the associated risk of adverse maternal and neonatal outcomes. We undertook an observational cohort study of all women who delivered a live or stillborn infant in Ontario, Canada, between 1 January 2010 and 31 March 2012 using birth record data from the Better Outcomes Registry & Network, Canadian Blood Services, and the Institute of Clinical Evaluative Sciences. Only a woman's first pregnancy within the study time frame was included for analysis. We excluded women 50 years of age at the time of delivery and multiple birth pregnancies. Data on all female donors who made whole blood donations between 1 January 2007 and 31 March 2012 were obtained from Canadian Blood Services. The primary newborn outcome was diagnosis of a small-for-gestational-age neonate (less than 10th centile). Secondary outcomes were preterm birth, stillbirth, APGAR <4 at 5 minutes, cord pH <7, neonatal death, maternal transfusion, infection, preecl sia, gestational hypertension, gestational diabetes, placental abruption, and maternal death. Regression models evaluated the effect of repeated donation and the time interval between donations and conception on neonatal and maternal outcomes while adjusting for important clinical and demographic risk factors. A total of 260 037 women delivered live or stillborn singleton infants between 1 January 2010 and 31 March 2012. A total of 7919 (3.0%) women were blood donors, with a mean of 2.43 ± 2.10 lifetime donations. Mean maternal age at the time of delivery for nondonors and donors was 30.30 ± 5.38 and 29.74 ± 4.94 years, respectively. Small for gestational age occurred in 23 706 (9.4%) of neonates born to nondonors and 526 (6.6%) of neonates born to donors. There was a reduction in the risk of small for gestational age with increasing number of lifetime donations (adjusted odds ratio 0.89 [0.86-0.92] per additional donation). For the prespecified secondary outcomes, we observed a reduction in the risk of low birth weight (adjusted odds ratio 0.95 [0.91-0.98] per additional donation). There was no association with other secondary neonatal or maternal outcomes except for maternal hypertension. Proximity of donation to conception had no effect on risk of a small-for-gestational age neonate. Our data suggest that there is no increased risk of deleterious neonatal and maternal outcomes associated with repeated blood donations prior to pregnancy. Although possibly a result of a healthy donor effect, our findings are reassuring to female donors and their children as well as to clinicians and blood system stakeholders seeking to inform policy decisions.
Publisher: Wiley
Date: 26-10-2022
DOI: 10.1111/TRF.17164
Publisher: American Physiological Society
Date: 11-1999
DOI: 10.1152/AJPCELL.1999.277.5.C987
Abstract: We tested the hypothesis that aging and insulin resistance interact to increase vascular dysfunction by comparing the function of isolated mesenteric resistance arteries in obese, insulin-resistant JCR:LA-cp rats and lean, insulin-sensitive rats of the same strain at 3, 6, 9, and 12 mo of age. The peak constrictor responses to norepinephrine, phenylephrine, and high potassium were elevated in arteries from obese rats. Responses to these agents increased with age in both obese and lean rats. An eicosanoid constrictor contributed substantially to vasoconstriction in the arteries from both lean and obese animals. Inhibition of nitric oxide synthase increased the vasoconstrictor response to norepinephrine in both obese and lean rats. This effect increased with age in lean rats only. Vascular relaxation in response to acetylcholine and sodium nitroprusside was impaired in the obese rats and did not alter with age. The results suggest that obese JCR:LA-cp rats have enhanced maximal constriction, which originates in the arterial smooth muscle and increases with age. There is evidence that the ability of the arteries to compensate for the enhanced contractility is impaired in obese rats, particularly with advanced age.
Publisher: Wiley
Date: 17-07-2021
DOI: 10.1111/TRF.16595
Abstract: Babesia microti has gained a foothold in Canada as tick vectors become established in broader geographic areas. B. microti infection is associated with mild or no symptoms in healthy in iduals but is transfusion‐transmissible and can be fatal in immunocompromised in iduals. This is the first estimate of clinically significant transfusion‐transmitted babesiosis (TTB) risk in Canada. The proportion of B. microti ‐antibody (AB)/nucleic acid lification test (NAT)‐positive whole blood donations was estimated at 5.5% of the proportion of the general population with reported Lyme Disease (also tick‐borne) based on US data. Monte Carlo simulation estimated the number and proportion of infectious red cell units for three scenarios: base, localized incidence (risk in Manitoba only), and donor study informed (prevalence from donor data). The model simulated 1,029,800 donations repeated 100,000 times for each. In the base scenario 0.5 (0.01, 1.75), B. microti ‐NAT‐positive donations would be expected per year, with 0.08 (0, 0.38) recipients suffering clinically significant TTB (1 every 12.5 years). In the localized incidence scenario, there were 0.21(0, 0.7) B. microti ‐NAT‐positive donations, with 0.04 (0, 0.14) recipient infections (about 1 every 25 years). In the donor study informed scenario, there were 4.6 (0.3, 15.8) B. microti ‐NAT‐positive donations expected, and 0.81 (0.05, 3.14) clinically significant TTB cases per year. The likelihood of clinically relevant TTB is low. Testing would have very little utility in Canada at this time. Ongoing pathogen surveillance in tick vectors is important as B. microti prevalence appears to be slowly increasing in Canada.
Publisher: Wiley
Date: 06-2021
DOI: 10.1111/VOX.13126
Abstract: Iron depletion is a side effect of blood donation. Agencies have developed policies to test donors and to extend inter‐donation intervals (IDIs) for in iduals with low ferritin levels. Ferritin testing, however, has an impact on product availability due to longer IDIs and the effect of test results on donor behaviour. In this paper we apply a model to evaluate the impact of ferritin testing in the Canadian donor population on whole blood donations. A discrete event simulation was adopted for the study. The model represents a population of in iduals that donate blood, are tested for ferritin levels, and may exit the system. Data for the simulation was derived from operational data, donor research studies from Canadian Blood Services and previously published sources. Red cell collections will decline by at least 3.1% and could decline by as much as 19.2% after ferritin testing is put in place. Requirements for new donors could rise by as much as 36.0%. The impact of ferritin testing on repeat donor behaviour, rather than extensions to the mandated inter‐donation interval, is the largest factor influencing declines in whole blood donations. Because behaviour changes following the receipt of a low ferritin result, blood agencies must ensure that donors with low ferritin are motivated to modify their lifestyle and, when healthy, return to the donor pool.
Publisher: Wiley
Date: 10-09-2017
DOI: 10.1111/VOXS.12367
Publisher: Wiley
Date: 24-10-2011
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.TRANSCI.2017.03.010
Abstract: Residual risk is estimated as the product of the incidence and the infectious window period, the time during which a blood donation could be infectious but the assay may not detect it. In 2011 nucleic acid multiplex testing (MPX) was implemented in 6 unit minipools (previously 24 unit minipools). MPX also included hepatitis B (HBV) NAT for the first time (complementing HBsAg screening) in addition to HIV-1 and hepatitis C (HCV) as before. We aimed to estimate window period risk-day equivalents for MPX, and the residual risk of viral infections in blood donations updated to reflect current incidence and testing. Transmissible disease conversions of repeat donations to Canadian Blood Services within the three-year period 2012-2014 ided by person-years estimated incidence for HIV, HCV and HBV (adjusted for transient viremia). Window period risk-day equivalents for MPX were estimated using a published method. Residual risk was the product of incidence and window period risk-day equivalents. 95% confidence intervals were estimated using Monte Carlo simulation of the window period risk-day equivalents and the incidence density 95% confidence intervals. The incidence rate per 100,000 person years for HIV was 0.28, HCV 1.0 and HBV 0.26. The residual risk of HIV was 1 per 21.4 million donations, HCV 1 per 12.6 million donations and HBV 1 per 7.5 million donations. The residual risk of infection is very low, similar to 2006-2009. The safety benefit of further shortening of the infectious window period is below the threshold to quantify.
Publisher: University of Toronto Press Inc. (UTPress)
Date: 11-10-2020
Abstract: Background: Cytomegalovirus (CMV) and Epstein–Barr virus (EBV) infections are common, causing significant morbidity in pregnancy (congenital CMV) and transplant recipients (CMV, EBV). Canadian prevalence data are needed to model disease burden and develop strategies for future vaccines. We estimated prevalence using screening data from blood donors and solid organ transplant (SOT) donors and recipients. Methods: We retrospectively analyzed CMV and EBV serology from Alberta SOT donors ( n = 3,016) and recipients ( n = 4,614) (1984–2013) and Canadian Blood Services blood donors ( n = 1,253,350) (2005–2014), studying associations with age, sex, organ, year, and geographic region. Results: CMV seroprevalence rises gradually with age. By age 70, CMV seropositivity ranged from 67% (blood donors) to 73% (SOT recipients). Significant proportions of women of child-bearing age were CMV-seronegative (organ donors, 44% SOT recipients, 43% blood donors, 61%). Blood donor CMV seroprevalence decreased from 48% in Western Canada to 30% in Eastern Canada. Women were more likely to be CMV-seropositive (ORs = 1.58, 1.45, and 1.11 for organ donors, SOT recipients, and blood donors, respectively) and EBV-seropositive (ORs = 1.87 and 1.46 for organ donors and SOT recipients, respectively). EBV prevalence rises rapidly, and by age 17–29 years, 81% of SOT recipients and 90% of organ donors were seropositive. Conclusions: Canada has relatively low and perhaps decreasing age-specific EBV and CMV prevalence, making Canadians vulnerable to primary infection-associated morbidity and suggesting benefit from future vaccines. Collection and analysis of routine serology screening data are useful for observing trends.
Publisher: Wiley
Date: 10-01-2019
DOI: 10.1111/TRF.15098
Abstract: The deferral for men who have sex with men (MSM) was reduced from a permanent deferral for MSM if even one time since 1977 to progressively shorter time deferrals of 5 years and 1 year in Canada. We assessed compliance with these deferrals and the impact on safety at Canadian Blood Services. Three anonymous online compliance surveys of male whole blood donors were carried out before and after implementation of successive changes. HIV rates and incidence were monitored from January 1, 2011, to August 14, 2018. Participation rates in the consecutive surveys were 49.7% before implementation, 36.3% after 5 years and 36.3% after 1 year. There was no difference before versus after implementation in male donors with MSM history in the past year (0.21%, 0.19%, 0.24% p = 0.70). The percentage of eligible MSM donors increased (0.13%, 0.66%, 1.21% p < 0.0001), with approximately 2500 eligible MSM donors with the 1-year deferral in place. HIV rates were less than 0.6 per 100,000 donations and unchanged after each policy change (p = 0.14 for trend). Incidence remained unchanged at 0.22 per 100,000 person-years before implementation, 0.54 per 100,000 after 5-year deferral, and no incident cases after 1-year deferral (p = 0.55). Progressively shorter time deferrals had no impact on noncompliance of MSM with a male partner in the past year. Contrary to modeling predictions, shorter time deferrals had no impact on HIV rates or incidence. There was a modest increase in eligible MSM in the donor pool after each shorter time deferral. These results support the safety of reducing deferral periods for MSM.
Publisher: Wiley
Date: 14-08-2013
DOI: 10.1111/TRF.12380
Abstract: The adequacy of communication and knowledge of donors and physicians regarding iron needs and the relationship between hemoglobin (Hb) and iron stores require evaluation to address donor iron deficiency. A prospective cohort study was performed on 550 successful donors and 50 donors deferred for low Hb (<125 g/L on repeat fingerstick). Donors participated in an on-clinic interview and had serum ferritin measured. They were mailed their results and recontacted regarding follow-up. Most donors are unaware of possible health impacts of donation and do not discuss donation with their physician. In successful donors, mean ferritin levels were 37 and 131 μg/L in first-time and reactivated (no donation for 2 years) females and males and 19 and 29 μg/L in frequent repeat females and males, respectively (p < 0.0001), with infrequent donors having intermediate results. Mean ferritin was 12 μg/L in donors deferred for low Hb. Twenty of 22 donors failing initial Hb testing and passing on repeat testing had ferritin below 25 μg/L. On follow-up, 63 of 164 donors (38%) with low ferritin were taking iron supplements 2 months postdonation. Iron deficiency is frequent, particularly in female donors and frequent donors. A fail on initial Hb testing followed by a pass on repeat testing is likely to be due to iron deficiency and borderline anemia. Donors and physicians need to be more aware of iron needs associated with blood donation and appropriate treatment for low iron stores.
Publisher: Wiley
Date: 28-04-2020
DOI: 10.1111/TRF.15777
Publisher: Wiley
Date: 16-03-2021
DOI: 10.1111/TRF.16349
Abstract: The use of pre− ost‐exposure prophylaxis (PrEP/PEP) may interfere with routine HIV screening. As a result, blood services worldwide have adopted a variety of deferral policies to mitigate increased residual risk. In this study, we evaluated the operational impact of modifying the donor health questionnaire (DHQ) to include explicit questions to assess PrEP/PEP exposure. We conducted a retrospective study between June 2019 and October 2020 of all blood donors attempting to donate at Canadian Blood Services. Sixteen‐months post‐implementation, we summarized self‐reported PrEP/PEP rates and their indications for use. We also assessed deferral rates and the sensitivity of using existing risk questions to defer people exposed to PrEP/PEP. Of 1,122,075 donations, 89 people (eight per 100,000 donations) reported PrEP (64%)/PEP (34%) use in the last 4 months. People exposed to PrEP were more likely to be men (94%) and taking PrEP for lifestyle reasons (87%). In contrast, indications for PEP use included occupational exposure (50%) and sexual assault (27%). Most donors who answered affirmatively to PrEP/PEP exposure were deferred (96%). If potential donors were not directly asked about their PrEP/PEP use, the majority would not have been deferred for any other reasons (PrEP 32/57 (56%) and PEP 15/30 (50%)). Not all blood services have adopted direct questions to identify PrEP/PEP exposure some rely on existing DHQ questions. In Canada, despite DHQ questions such as medication use in the last 3‐days, more than half of people exposed to PrEP/PEP would not have been identified and deferred.
Publisher: Wiley
Date: 03-2021
DOI: 10.1111/VOX.13084
Publisher: Wiley
Date: 09-05-2023
DOI: 10.1111/TRF.17393
Abstract: In Canada the time deferral for gay, bisexual, and other men who have sex with men (gbMSM) was progressively shortened (lifetime, 5 years, 1 year, 3 months). Here we describe trends in syphilis rates (a potential sexual risk marker) and risk behaviors from blood donors in the past 12 years. Syphilis positivity in 10,288,322 whole blood donations (January 1, 2010–September 10, 2022) and gbMSM deferral time periods, donation status, age, and sex were analyzed with logistic regression. Overall, 26.9% syphilis positive and 42.2% controls (matched 1:4) participated in risk factor interviews analyzed by logistic regression. Syphilis rates were higher in first‐time donors (OR 27.0, 95% CI 22.1–33.0), in males (OR 2.3, 1.9–2.8) and with the 3‐month deferral (OR 3.4, 2.6–4.3) during which the increase was greater for first‐time males ( p .001) but similar for male and female repeat donors ( p .05). Among first‐time donors, histories of intravenous drug use (OR 11.7, 2.0–69.5), male‐to‐male sex 7.8 (2.0–30.2) and birth in a high prevalence country (OR 7.6, 4.4–13.0) predicted syphilis positivity among repeat donors, history of male‐to‐male sex (OR 33.5, CI 3.5–317.0). All but 1 gbMSM syphilis‐positive donors were noncompliant with the gbMSM deferral. About a quarter of first‐time interviewed case donors had history of syphilis 44% were born in a high‐prevalence country. Rising syphilis rates in donors correlates with the general population epidemic. Recent infection rates rose similarly in males and females. GbMSM history may contribute to donor syphilis rates but shortening time deferrals appears unrelated.
Publisher: Wiley
Date: 25-04-2007
Publisher: Elsevier BV
Date: 12-2020
DOI: 10.1111/AJT.16066
Publisher: Elsevier BV
Date: 09-1996
DOI: 10.1016/S0026-0495(96)90009-8
Abstract: The purpose of the study was to examine the contribution of alterations in lipoprotein metabolism to the progression of very-low-level albuminuria in insulin-dependent diabetes mellitus (IDDM). We measured serum concentrations of lipids, lipoproteins, and apolipoproteins in 53 normoalbuminuric diabetic patients without overt hypertension, whom we restudied after 10 years. Albuminuria was measured as the urinary albumin to creatinine ratio (UA/UC) in repeated early-morning s les. Over 10 years, UA/UC increased significantly (P < .001), and five patients (9.4%) progressed to microalbuminuria. The increase in albuminuria was significantly and positively related to the baseline serum concentrations of total cholesterol (P < .05), low-density lipoprotein (LDL) cholesterol (P = .05), non-high-density lipoprotein (HDL) cholesterol (P < .05), and apolipoprotein (apo) B (P < .001), but no significant associations were found with triglycerides, HDL cholesterol, apo A-1, or lipoprotein(a) [Lp(a)]. The relative risk of developing microalbuminuria for a serum apo B concentration more than 1.1 g/L was 3.8 (95% confidence interval [CI], 1.9 to 7.7). In multiple linear regression analysis, serum apo B (P < .05) and glycated hemoglobin ([HbA] P < .05) at baseline were significant independent predictors of the increase in albuminuria, with no significant associations found for sex, smoking, duration of diabetes, mean arterial blood pressure (BP), or family history of cardiovascular disease and hypertension the regression model predicted 42% of the variation in UA/UC at 10 years. The findings suggest that an abnormality in the metabolism of apo B may be independently associated with progression of very-low-level albuminuria and possibly with the development of early nephropathy in IDDM patients.
Publisher: American Society for Microbiology
Date: 27-04-2022
DOI: 10.1128/SPECTRUM.02702-21
Abstract: The BNT162b2 and mRNA-1273 mRNA SARS-CoV-2 vaccines have demonstrated high efficacy for preventing short-term COVID-19. However, comparative long-term effectiveness is unclear, especially pertaining to the Delta variant.
Publisher: American Society for Microbiology
Date: 26-10-2022
DOI: 10.1128/SPECTRUM.02811-22
Abstract: The United States Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the use of COVID-19 convalescent plasma (CCP) to treat hospitalized patients with COVID-19 in August 2020. However, by 4 February 2021, the FDA had revised the convalescent plasma EUA.
Publisher: Wiley
Date: 23-05-2023
DOI: 10.1111/TRF.17398
Abstract: In 2021, Canada implemented a pilot plasma program allowing some sexually active men who have sex with men (including but not limited to gay and bisexual men gbMSM) to donate plasma. Changes to plasma donation policy could help address inequities in access to plasma donation and increase Canada's domestically collected plasma supply if more gbMSM donate as a result. We aimed to (1) examine views regarding plasma donation and the pilot program prior to implementation and (2) identify modifiable theory‐informed predictors of gbMSM's intention to donate plasma. We developed, piloted, and disseminated a questionnaire informed by the Theoretical Domains Framework (TDF). We recruited gbMSM in London (ON) and Calgary (AB) to an anonymous, online cross‐sectional survey. A total of 246 gbMSM completed the survey. On scales from 1 (strongly disagree) to 5 (strongly agree), general intention to donate was high (mean = 4.24 SD = 0.94). The pilot program itself was mostly acceptable (mean = 3.71, SD = 1.16), but the intention to donate under the unique requirements of the pilot program was lower than general intention (mean = 3.58 SD = 1.26). Two domains from the theoretical domains framework (TDF) (beliefs about consequences of donating plasma and social influences) were independently associated with general intention to donate. The pilot plasma program as an incremental step toward more inclusive policies was mostly viewed as acceptable by the impacted communities. Historical and ongoing exclusions create unique barriers to donation. There are clear opportunities for developing theory‐informed interventions to support gbMSM to donate plasma as policies continue to become more inclusive and more become eligible to donate.
Publisher: Wiley
Date: 08-2019
DOI: 10.1111/VOX.12826
Abstract: Eight published studies modelled the impact of changing from a lifetime to time-limited deferral for men who have sex with men (MSM) each predicted greater risk impact than has been observed. This study uses these previous efforts to develop an 'optimized' model to inform future changes to MSM deferrals. HIV residual risk was calculated using observed HIV incidence revalence prior to the change in MSM deferral, then with the additional MSM expected under a 12-month deferral for five compliance scenarios, and finally using data observed after implementation of the deferral. Monte Carlo simulation calculated 95% confidence intervals (CI). The architecture of reviewed models was sound, and two were selected for combination into the optimized model. HIV risk estimated by this in the UK under MSM lifetime deferral was 0·102 (95% CI: 0·050-0·172) per million. The model predicted from a 27·8% decrease to a 47·6% increase depending upon compliance pre-implementation of the 12-month deferral. A decrease of 0·9% was observed post-implementation. For Canada, HIV risk under a 5-year deferral was 0·050 (95% CI: 0·00003-0·122) per million. Pre-implementation of the 12-month deferral, the model predicted from 30·2% decrease to 10-fold increase. A decrease of 47·0% was observed after implementation. The optimized model predicted HIV risk under 12-month MSM deferral in UK and Canada would remain low, and this was confirmed post-implementation. While the model is adaptable to other deferral scenarios, improved data quality would improve precision, particularly estimates of incidence in in iduals likely to donate.
Publisher: Springer Science and Business Media LLC
Date: 25-04-2023
DOI: 10.1186/S12889-023-15424-1
Abstract: Canada has incrementally reduced restrictions to blood and plasma donation that impact men who have sex with men, gay, bisexual, and queer men, and some Two Spirit, transgender and non-binary in iduals (MSM/2SGBTQ+). Prior to the launch of a pilot program in 2021 enabling some MSM/2SGBTQ + to donate source plasma, we explored the acceptability of the program among in iduals who could become eligible to donate in the program. We invited men identifying as MSM/2SGBTQ + to participate in two consecutive semi-structured interviews to explore their views on blood and plasma donation policy, plasma donation, and the proposed Canadian plasma donation program. Interview transcripts were analyzed thematically and acceptability-related themes were mapped onto the Theoretical Framework of Acceptability. Twenty-seven men identifying as having sex with men participated in 53 interviews. Eighteen themes were mapped onto the seven construct domains of the Theoretical Framework of Acceptability. Underlying all aspects of acceptability was a tension between four primary values influencing participants’ views: altruism, equity, supply sufficiency, and evidence-based policy. The program was viewed as welcome progress on a discriminatory policy, with many excited to participate, yet tension with inequitable aspects of the program undermined support for the program and interest to contribute to it. The high demands of the program are unique for MSM/2SGBTQ + and are only tolerable as part of a program that is an incremental and instrumental step to more equitable donation policies. Findings highlight past experiences of exclusion in Canada as a unique and critical part of the context of the donation experience among MSM/2SGBTQ+. Despite the program’s goals of greater inclusivity of MSM/2SGBTQ + in iduals, the anticipated experience of the program included continued stigmatization and inequities. Future research should seek to understand the experienced views of MSM/2SGBTQ + donors to ensure that as policies change, policies are implemented equitably.
Publisher: CMA Impact Inc.
Date: 08-01-2023
Publisher: Elsevier BV
Date: 04-2016
Publisher: Wiley
Date: 11-1997
DOI: 10.1002/(SICI)1096-9136(199711)14:11<974::AID-DIA495>3.0.CO;2-I
Publisher: Wiley
Date: 17-05-2016
DOI: 10.1111/TRF.13635
Abstract: A 95% confidence interval (CI) of the mean is a range with an upper and lower number calculated from a s le. Because the true population mean is unknown, this range describes possible values that the mean could be. If multiple s les were drawn from the same population and a 95% CI calculated for each s le, we would expect the population mean to be found within 95% of these CIs. CIs are sensitive to variability in the population (spread of values) and s le size. When used to compare the means of two or more treatment groups, a CI shows the magnitude of a difference between groups. This is helpful in understanding both the statistical significance and the clinical significance of a treatment. In this article we describe the basic principles of CIs and their interpretation.
Publisher: Wiley
Date: 10-01-2008
DOI: 10.1111/J.1537-2995.2007.01602.X
Abstract: Because Trypanosoma cruzi (T. cruzi) infection in Canada and the United States is largely contracted in endemic countries, targeted testing of blood donors with risk travel may improve safety. The operational validity of a travel question suitable for donor screening was tested, and it was field-tested. After 1331 donors completed a short travel question, operational validity was assessed by detailed travel histories in face-to-face interviews. Two nationwide donor surveys were carried out assessing donor responses to similar travel questions in 2001 (13,623 donors) and in 2006 (20,037 donors). All donors in Toronto, Ontario, answered a travel question in 1997 and those born in or who spent 6 months or more in Mexico, Central America, or South America were tested for antibody to T. cruzi. There was 97.3 percent agreement between the travel question and detailed interviews, with 15 donors (1.1%) failing to acknowledge risk travel (false-negative questioning responses). Of these, 6 donors were born there and 7 others had less than 1 year of cumulative travel. In 2001 and 2006, there were 2.1 and 2.0 percent of donors with risk travel, respectively, but 16.5 and 11.2 percent of these donors were identified only because they were born there (travel not acknowledge). There were 1337 (1.6%) donors in Toronto in 1997 with risk travel and none were positive for the presence of T. cruzi antibody. Donors can answer a short question about cumulative time in Latin America with similar accuracy to detailed questioning, but screening questions should also include country of birth.
Publisher: Wiley
Date: 31-08-2021
DOI: 10.1111/VOX.13198
Abstract: We describe the third documented case of autochthonous human babesiosis in Canada and the second in a Canadian blood donor. Multiple laboratory investigations were carried out on the donor and the immunocompromised recipient of an associated, potentially infectious red blood cell product. The donor had not travelled except for outdoor exposure in south‐eastern Manitoba, followed by illness and hospital admission. The donor had a notable parasitaemia, positive for Babesia microti using whole blood nucleic acid testing (NAT). The recipient was negative for B. microti by both serology and NAT. There was no evidence of transfusion‐transmitted babesiosis.
Publisher: Wiley
Date: 19-07-2007
DOI: 10.1111/J.1537-2995.2007.01396.X
Abstract: The benefit of introducing anti-hepatitis B core antigen (HBc) screening for intercepting potentially infectious donations missed by hepatitis B surface antigen (HBsAg) screening in Canada was studied. Anti-HBc testing of all donations was implemented in April 2005, along with antibody to hepatitis B surface antigen (anti-HBs) and hepatitis B virus (HBV) DNA supplemental testing of anti-HBc repeat-reactive, HBsAg-negative donations. The proportion of potentially infectious donations intercepted by anti-HBc over the initial 18 months of testing was calculated based on three assumptions relating infectivity of HBV DNA-positive units to anti-HBs levels. Lookback was conducted for all DNA-positive donations. Of 493,344 donors, 5,585 (1.13%) were repeat-reactive for the presence of anti-HBc, with 29 (0.52%) being HBV DNA-positive and HBsAg-negative. The proportion of potentially infectious donations intercepted by anti-HBc screening was 1 in 17,800 if all HBV DNA-positive donations were infectious, 1 in 26,900 if infectivity was limited to donations with an anti-HBs level of not more than 100 mIU per mL, and 1 in 69,300 if only donations with undetectable anti-HBs were infectious. For 279 components in the lookback study, no traced recipients were HBsAg-positive and 7 recipients were anti-HBc-reactive in association with 4 donors, 3 of whom had an anti-HBs level of more than 100 mIU per mL and 1 of whom had a level of 61 mIU per mL. Implementation of anti-HBc screening reduced the risk of transfusing potentially infectious units by at least as much as had been expected based on the literature. The lookback did not provide proof of transfusion transmission of HBV from HBV DNA-positive, anti-HBc-reactive, HBsAg-negative donors but it did not establish lack of transmission either.
Publisher: Wiley
Date: 04-10-2022
DOI: 10.1111/TRF.17140
Abstract: Surveillance of blood donors is fundamental to safety of the blood supply. Such data can also be useful for public health policy but tend to be underutilized. When the COVID‐19 pandemic arrived, blood centers around the world measured blood donor SARS‐CoV‐2 seroprevalence to inform public health policy. There is now a movement toward blood centers becoming more involved in public health research and surveillance post‐pandemic. However, blood donors are a healthy population and not representative of all segments of the general population. In this article, we explain how blood centers can evaluate their donor base to understand which part of the general population they are representative of. Methodologic approaches for evaluating s les relative to the target population were reviewed. Blood donor data that are available to most blood centers were identified and application to assess representativeness of blood donors was evaluated. Key aspects of blood donor data to compare with general population data include donor selection criteria, health indicators, geography, and demographics. In some cases, statistical adjustment can improve representativeness. Comparing key blood donor data with corresponding general population data can define the subset of the general population for which a particular blood center's donors may be representative of. We suggest that donors are an ideal convenience population for surveillance of infectious agents which are frequently asymptomatic and main routes of transmission are not deferrable, for studying the natural history of disease in an initially well population, and for vaccination serology surveillance.
Publisher: American Society for Microbiology
Date: 24-10-2023
DOI: 10.1128/JCM.01268-22
Publisher: Wiley
Date: 23-02-2021
DOI: 10.1111/TRF.16296
Abstract: Case detection underestimates the burden of the COVID‐19 pandemic. Following the first COVID‐19 wave, we estimated the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) among blood donors across Canada. This serial cross‐sectional study was conducted between May 9 and July 21, 2020 from blood donors donating at all Canadian Blood Services locations. We used the Abbott Architect assay to detect SARS‐CoV‐2 IgG antibodies from retention plasma. Seroprevalence was standardized to population‐level demographics and assay characteristics were adjusted using the Rogan‐Gladen equation. Results were stratified by region, age, ethnicity, ABO groups, and quantiles of material and social deprivation indices. Temporal trends were evaluated at 2‐week intervals. Univariate and multivariate logistic regression compared SARS‐CoV‐2 reactive to non‐reactive donors by sociodemographic variables. Overall 552/74642 donors, had detectable antibodies, adjusted seroprevalence was 7.0/1000 donors (95% CI 6.3, 7.6). Prevalence was differential by geography, Ontario had the highest rate, 8.8/1000 donors (7.8, 9.8), compared to the Atlantic region 4.5/1000 donors (2.6, 6.4) adjusted odds ratio (aOR) 2.2 (1.5, 3.3). Donors that self‐identified as an ethnic minority were more likely than white donors to be sero‐reactive aOR 1.5 (1.2, 1.9). No temporal trends were observed. Worldwide, blood services have leveraged their operational capacity to inform public health. While % of Canadians did not show humoral evidence of past infection, we found regional variability and disparities by ethnicity. Seroprevalence studies will continue to play a pivotal role in evaluating public health policies by identifying trends and monitor disparities.
Publisher: Wiley
Date: 24-05-2018
DOI: 10.1111/PETR.13229
Abstract: Assignment of CMV infection status in infants awaiting SOT is challenging as passive maternal antibody can lead to false-positive serology. Since 2000, our protocol has recommended sending throat and urine s les for CMV viral detection, culture, or NAAT, for CMV-seropositive infants <18 months awaiting SOT. We reviewed pretransplant CMV serology for 152 infants and, for CMV seropositives, examined relationships between CMV IgG OD values, age, and CMV viral detection to explore time to clearance of maternal CMV IgG and evaluate viral detection in assignment of pretransplant CMV infection status. The proportion of CMV-seropositive infants decreased from 52% in infants 0-6 months of age to 28% in those 12-18 months. Among CMV-seropositive infants, median OD was significantly higher in the 6- to 12- and 12- to 18-month groups compared to the 0- to 6-month group. Distribution of OD by age group suggested that maternal antibody cleared before 12 months. Of 59 eligible CMV-seropositive infants, 49 (83%) had CMV viral detection studies and 18 of 49 (36.7%) had detectable CMV: 9 of 30 (30.0%) infants 0-6 months, 7 of 15 (46.7%) infants 6-12 months, and 2 of 4 (50.0%) infants 12-18 months. CMV viral detection studies are useful to confirm positive CMV infection status in CMV-seropositive infants awaiting SOT. Maternal CMV IgG likely clears before 12 months.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Wiley
Date: 09-2020
DOI: 10.1111/TRF.16056
Publisher: Wiley
Date: 11-12-2012
DOI: 10.1111/TRF.12011
Abstract: Adverse donor reactions can result in injury and decrease the likelihood of donor return. Reaction reports captured in the blood center's database provide an incomplete picture of reaction rates and risk factors. We performed an anonymous survey, mailed to 40,000 donors in 2008, including questions about symptoms, height, weight, sex, and donation status. Reaction rates were compared to those recorded in our database. Possible risk factors were assessed for various reactions. The response rate was 45.5%. A total of 32% of first-time and 14% of repeat donors reported having any adverse symptom, most frequently bruising (84.9 per 1000 donors) or feeling faint or weak (66.2 per 1000). Faint reactions were two to eight times higher than reported in our database, although direct comparison was difficult. Younger age, female sex, and first-time donation status were risk factors for systemic and arm symptoms. In females, low estimated blood volume (EBV) was a risk factor for systemic symptoms. Only 51% of donors who consulted an outside physician also called Canadian Blood Services. A total of 10% of first-time donors with reactions found adverse effects information inadequate. This study allowed us to collect more information about adverse reactions, including minor symptoms and delayed reactions. Based on our findings of the risk factors and frequency of adverse reactions, we are implementing more stringent EBV criteria for younger donors and providing more detailed information to donors about possible adverse effects and their management.
Publisher: Wiley
Date: 28-04-2010
DOI: 10.1111/J.1537-2995.2009.02550.X
Abstract: The Canadian blood supply has been screened for West Nile virus (WNV) since 2003. A strategy for targeted in idual-donation nucleic acid testing (ID-NAT) was implemented in 2004 to identify potentially infectious donations that may be missed by minipool (MP) testing. In 2007, Canada experienced a larger epidemic than in previous years providing an opportunity to evaluate the ID-NAT triggering algorithm in higher-risk areas. A specially created database and internal-external communication identified regions for targeted ID-NAT using MP and community triggers. WNV-positive donations identified by ID-NAT were reexamined in MP to assess the efficacy of targeted ID-NAT in identifying potentially infectious donations that may have been missed by MP testing. WNV-positive donation data from 2006 and 2007 were analyzed to examine temporal and geographic trends. A telephone survey about symptoms was carried out after the 2007 season. In total 78 WNV-positive donations were identified (66 true-positives and four false-positives being in 2007). Most positive donations were in the late summer, concentrated in the same western provinces as community cases. Fifty-two donations were identified by ID-NAT and 46% were consistently positive in MP. Of the other 54%, 74% were immunoglobulin (Ig)M- and/or IgG-positive. Fifty-six percent of donors experienced mostly mild symptoms before or after donation (but all said they were well at the time of donation). WNV-positive donations correspond geographically with the epidemic. MP testing identifies most potentially infectious donations with a smaller potential benefit from targeted ID-NAT. Mild symptoms are common but may not deter donation.
Publisher: Public Library of Science (PLoS)
Date: 23-09-2021
DOI: 10.1371/JOURNAL.PONE.0257743
Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence studies bridge the gap left from case detection, to estimate the true burden of the COVID-19 pandemic. While multiple anti-SARS-CoV-2 immunoassays are available, no gold standard exists. This serial cross-sectional study was conducted using plasma s les from 8999 healthy blood donors between April-September 2020. Each s le was tested by four assays: Abbott SARS-Cov-2 IgG assay, targeting nucleocapsid (Abbott-NP) and three in-house IgG ELISA assays (targeting spike glycoprotein, receptor binding domain, and nucleocapsid). Seroprevalence rates were compared using multiple composite reference standards and by a series of Bayesian Latent Class Models. We found 13 unique diagnostic phenotypes only 32 s les (0.4%) were positive by all assays. None of the in idual assays resulted in seroprevalence increasing monotonically over time. In contrast, by using the results from all assays, the Bayesian Latent Class Model with informative priors predicted seroprevalence increased from 0.7% (95% credible interval (95% CrI) 0.4, 1.0%) in April/May to 0.7% (95% CrI 0.5, 1.1%) in June/July to 0.9% (95% CrI 0.5, 1.3) in August/September. Assay characteristics varied over time. Overall Spike had the highest sensitivity (93.5% (95% CrI 88.7, 97.3%), while the sensitivity of the Abbott-NP assay waned from 77.3% (95% CrI 58.7, 92.5%) in April/May to 64.4% (95% CrI 45.6, 83.0) by August/September. Our results confirmed very low seroprevalence after the first wave in Canada. Given the dynamic nature of this pandemic, Bayesian Latent Class Models can be used to correct for imperfect test characteristics and waning IgG antibody signals.
Publisher: Wiley
Date: 17-07-2013
DOI: 10.1111/TME.12057
Abstract: Blood donors in Canada have been tested for Human T-Cell Lymphotropic Virus (HTLV) since 1990. We report the epidemiology, risk factors and lookback/traceback of HTLV-positive donors/recipients. The annual HTLV rate was calculated from 1990 to 2010. Residual risk was estimated as the product of incidence and window period. Twenty-nine HTLV-positive donors and 116 matched controls (ratio 1 : 4) were interviewed about risk factors. For HTLV-positive donations, lookback investigations involved identification of all previous donations, and attempting to locate and test recipients. Traceback was initiated when transfusion transmission was queried for HTLV-positive blood recipients. All donors of products that the recipient received were identified, with an attempt to locate and test them. The HTLV rate decreased from 9.35 per 100,000 donations in 1990 to 1.11 in 2010. The residual risk of infection was 1 in 7.6 million donations. In logistic regression birth overseas (OR 18.7), history of sexually transmitted diseases (OR 32.9), sex with unknown background (OR 5.4) and blood transfusion (OR 8.9) were significant predictors. In the lookback study, of 109 HTLV-positive donors, 508 components were transfused, of whom 147 recipients were tested and 18 (12%) were positive. All were transfused prior to the implementation of donor testing. Twenty-three traceback investigations were requested involving 324 transfused untested products,of whom 219 (67.6%) of donors were tested and 13 (6%) were positive for HTLV. With testing of the blood supply, the risk from HTLV is very low and while most HTLV-positive donors have risk factors, deferrable risk is rare.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2022
DOI: 10.1161/CIR.0000000000001017
Abstract: The International Liaison Committee on Resuscitation initiated a continuous review of new, peer-reviewed published cardiopulmonary resuscitation science. This is the fifth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations a more comprehensive review was done in 2020. This latest summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation task force science experts. Topics covered by systematic reviews in this summary include resuscitation topics of video-based dispatch systems head-up cardiopulmonary resuscitation early coronary angiography after return of spontaneous circulation cardiopulmonary resuscitation in the prone patient cord management at birth for preterm and term infants devices for administering positive-pressure ventilation at birth family presence during neonatal resuscitation self-directed, digitally based basic life support education and training in adults and children coronavirus disease 2019 infection risk to rescuers from patients in cardiac arrest and first aid topics, including cooling with water for thermal burns, oral rehydration for exertional dehydration, pediatric tourniquet use, and methods of tick removal. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, according to the Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations or good practice statements. Insights into the deliberations of the task forces are provided in Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces listed priority knowledge gaps for further research.
Publisher: BMJ
Date: 05-2023
DOI: 10.1136/BMJOPEN-2022-071397
Abstract: Among persons with immune-mediated inflammatory diseases (IMIDs) who received SARS - CoV-2 vaccines, we compared postvaccine antibody responses and IMID disease activity/states. Single-centre prospective cohort study. Specialty ambulatory clinics in central Canada. People with inflammatory arthritis (n=78 77% rheumatoid arthritis), systemic autoimmune rheumatic diseases (n=84 57% lupus), inflammatory bowel disease (n=93 43% Crohn’s) and multiple sclerosis (n=72 71% relapsing-remitting) (female 79.4%, white 84.7%, mean (SD) age 56.0 (14.3) years) received COVID-19 vaccinations between March 2021 and September 2022. Postvaccination anti-spike, anti-receptor binding domain (anti-RBD) and anti-nucleocapsid (anti-NC) IgG antibodies tested by multiplex immunoassays compared across vaccine regimens and with responses in 370 age-matched and sex-matched vaccinated controls. COVID-19 infection and self-reported IMID disease activity/state. Most (216/327, 66.1%) received homologous messenger RNA (mRNA) (BNT162b2 or mRNA1273) vaccines, 2.4% received homologous ChAdOx1 and 30.6% received heterologous vaccines (23.9% ChAdOx1/mRNA, 6.4% heterologous mRNA) for their first two vaccines (V1, V2). Seroconversion rates were 52.0% (91/175) for post-V1 anti-spike and 58.9% (103/175) for anti-RBD 91.5% (214/234) for post-V2 anti-spike and 90.2% (211/234) for anti-RBD and were lower than controls (post-V2 anti-spike 98.1% (360/370), p .0001). Antibody titres decreased 3 months after V2 but increased 1 month after the third vaccine (V3) and 1 month after the fourth vaccine (V4) (BAU/mL median (IQR), anti-spike 1835 (2448) 1 month post-V2, 629.1 (883.4) 3 months post-V2, 4757.5 (7033.1) 1 month post-V3 and 4356.0 (9393.4) 1 month post-V4 anti-RBD 1686.8 (2199.44) 1 month post-V2, 555.8 (809.3) 3 months post-V2, 4280.3 (6380.6) 1 month post-V3 and 4792.2 (11 673.78) 1 month post-V4). If primed with a vector vaccine, an mRNA vaccine increased antibody titres to those comparable to homologous mRNA vaccines. Anti-RBD and anti-spike titres were higher in anti-NC seropositive (n=31 25 participants) versus seronegative s les (BAU/mL median (IQR) anti-RBD 11 755.3 (20 373.1) vs 1248.0 (53 278.7) anti-spike 11 254.4 (15 352.6) vs 1313.1 (3106.6) both p .001). IMID disease activity/state and rates of self-reported moderate or severe IMID flare were similar across vaccinations. Heterologous COVID-19 vaccination improves seroconversion rates following a vector vaccine and does not lead to IMID disease flare. IMIDs benefit from at least three vaccines.
Publisher: Wiley
Date: 09-04-2021
DOI: 10.1111/VOX.13107
Abstract: Efficiency in mitigating HIV transmission risk by transfusion may vary internationally. We compared HIV prevalence and incidence in blood donors across different jurisdictions in relation to those rates in the general population and differences in deferral practices. Data from 2007 to 2016 were collected in Australia, Brazil (São Paulo), Canada, England, France, Italy, Ireland, Japan, the Netherlands, New Zealand, Norway, Spain (Basque Country), USA (Vitalant) and Wales. For each country/region, the number of HIV antibody‐positive donations and nucleic acid testing (NAT)‐only‐positive donations was broken down according to first‐time or repeat donor status, along with the relevant denominators. There is a modest correlation between HIV prevalence among first‐time donors and HIV prevalence in the general population. However, rates of HIV‐positive donations in repeat donors, a proxy for incidence, do not correlate with incidence rates in the general population. Rates in donors from Italy and Basque Country, where deferral criteria for men having sex with men are less stringent, are higher compared with most other jurisdictions. Rates of NAT‐only‐positive donations are extremely low and do not differ significantly after adjustment for multiple comparisons. Donor HIV rates are only weakly associated with those observed in the general population. Countries with less stringent deferral criteria have higher HIV rates in their donor population, but the rates remain very low.
Publisher: Springer Science and Business Media LLC
Date: 30-09-2021
Publisher: Wiley
Date: 29-04-2021
DOI: 10.1111/VOX.13100
Abstract: Access to large pools of healthy adult donors advantageously positions blood component providers to undertake anti‐SARS‐CoV‐2 seroprevalence studies. While numerous seroprevalence reports have been published by blood operators during the COVID‐19 pandemic, details on the assay used has not been well documented. The objectives of this study were to evaluate the ersity of assays being used by blood operators and assess how this may affect seroprevalence estimates. We surveyed 49 blood component providers from 39 countries. Questionnaire included information on the number and identity of assays used, the detected immunoglobulin(s) and target antigen, and performance characteristics (sensitivity, specificity). Thirty‐eight of the 49 contacted blood suppliers provided at least partial responses. The results indicate that 19 commercial and five in‐house serology assays have been used by surveyed blood operators. The Abbott SARS‐CoV‐2 IgG assay was the most commonly used kit and utilized by 15 blood suppliers. Two assays did not detect IgG, but detected either IgM/IgA or IgM. 68·2% of assays targeted the spike protein and 50% the nucleocapsid protein, while 18·2% targeted both viral proteins. The sensitivity and specificity of IgG‐specific assays ranged from 71·9% to 100% and from 96·2% to 100%, respectively. As of 18 October 2020, the seroprevalence was below 5% in 10 of 14 countries reporting. Our results highlight the ersity of assays being used. Analyses comparing blood donor seroprevalence across countries should consider assay characteristics with optimization of signal/cut‐off ratios and consistent methodology to adjust for waning antibody.
Publisher: Wiley
Date: 03-12-2021
DOI: 10.1111/VOX.13221
Abstract: Blood donors are increasingly being recognized as an informative resource for surveillance. We aimed to review severe acute respiratory syndrome coronavirus 2 seroprevalence studies conducted among blood donors to investigate methodological biases and provide guidance for future research. We conducted a scoping review of peer‐reviewed and preprint publications between January 2020 and January 2021. Two reviewers used standardized forms to extract seroprevalence estimates and data on methodology pertaining to population s ling, periodicity, assay characteristics, and antibody kinetics. National data on cumulative incidence and social distancing policies were extracted from publicly available sources and summarized. Thirty‐three studies representing 1,323,307 blood donations from 20 countries worldwide were included (s le sizes ranged from 22 to 953,926 donations). The majority of the studies (79%) reported seroprevalence rates % (ranging from 0% to 76% [after adjusting for waning antibodies]). Overall, less than 1 in 5 studies reported standardized seroprevalence rates to reflect the demographics of the general population. Stratification by age and sex were most common (64% of studies), followed by region (48%). A total of 52% of studies reported seroprevalence at a single time point. Overall, 27 unique assay combinations were identified, 55% of studies used a single assay and only 39% adjusted seroprevalence rates for imperfect test characteristics. Among the nationally representative studies, case detection was most underrepresented in Kenya (1:1264). By the end of 2020, seroprevalence rates were far from reaching herd immunity. In addition to differences in community transmission and erse public health policies, study designs and methodology were likely contributing factors to seroprevalence heterogeneity.
Publisher: Oxford University Press (OUP)
Date: 05-10-2022
Abstract: The relationship between antibodies to wild-type severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens and the risk of breakthrough infections is unclear, especially during circulation of the Omicron strain. We investigated the association of anti-spike and anti-receptor binding domain antibody levels and the risk of subsequent breakthrough coronavirus disease 2019 (COVID-19). We included adult paramedics from an observational cohort study who received ≥ 2 mRNA vaccines but did not have COVID-19 before the blood collection. Higher postvaccination antibody levels to wild-type SARS-CoV-2 antigens were associated with a reduced risk of COVID-19. Further research into clinical utility of antibody levels, to inform a threshold for protection and timing of boosters, should be prioritized.
Publisher: Wiley
Date: 11-2008
DOI: 10.1111/J.1537-2995.2008.01845.X
Abstract: The residual risk of hepatitis B is higher than for other markers such as human immunodeficiency virus and hepatitis C virus in nonendemic countries. Evaluating the potential for further risk reduction requires a better understanding of the relationship between donor selection criteria, immigration from endemic countries, and public health vaccination strategies. Age and sex trends of hepatitis B surface antigen (HBsAg)-positive donors from 1997 to 2006 were analyzed using a Poisson model. All HBsAg-positive donors in 2005/2006 plus four matched control donors for every HBsAg-positive donor who participated were invited to participate in a risk factor interview and predictors of HBsAg positivity identified by logistic regression. A survey of 40,000 donors who did not react for all markers asked about vaccination history and country of birth. Most HBsAg-positive donations were from first-time donors (86%), have been decreasing in donors under the age of 30 (p < 0.01), and were correlated with geographic regions with more donors from higher-prevalence countries (p < 0001). Birth in a higher-prevalence country predicted HBsAg positivity (p < 0.01). Fifty-six percent of donors reported being vaccinated for hepatitis including approximately 80 percent of donors under age 30 who reported being vaccinated as part of regular school programs. HBsAg-positive donations are decreasing in donors under age 30, those most frequently vaccinated through provincial vaccination programs. HBsAg-positive donations largely reflect immigration from high-prevalence countries without other deferrable risk factors, mainly chronic cases that will be detected by current testing. Furthermore, risk of incident infections should decrease with increasing vaccination rates in donors, especially the younger cohort now receiving universal vaccination.
Publisher: Wiley
Date: 16-06-2016
DOI: 10.1111/TRF.13691
Abstract: Informing donors of their ferritin status is one possible mitigating strategy to reduce iron deficiency in donors. We evaluated the impact of informing donors of their ferritin status on their donation frequency, understanding of iron needs, and actions to improve iron intake 2 years after their inclusion in a prospective observational cohort study. Informing donors of low ferritin results decreased return rate in first-time and repeat donors, and the median number of donations declined from three to two donations/year in returning donors with low ferritin on index donation compared to an increase from 1.5 to 2.5 donations/year in donors with normal ferritin. An electronic questionnaire demonstrated that approximately 60% of low ferritin donors saw their primary medical practitioner, and half of this group started iron. Qualitative interviews revealed suboptimal understanding of iron needs and poor compliance with iron supplementation. Providing donors with results of ferritin testing may reduce return rates and donation frequency in the 2 years after testing. Simply providing donors with ferritin results and an information sheet is often inadequate to improve donors' understanding of iron needs and may not lead to a substantive increase in iron intake over time.
Publisher: Wiley
Date: 16-10-2012
DOI: 10.1111/J.1423-0410.2012.01656.X
Abstract: In China, paid donation is prohibited by law. There is little literature assessing donor motivation in China, and comparison with western countries such as Canada is important in understanding the application of Western literature. We compared motivational factors in donors from the city of Xi'an, China, with Canadian donors matched for age, sex and donation status. A total of 218 donors in Xi'an completed an interview about motivation as did 218 Canadian donors matched for age, sex and donation status. Frequencies and percentages of responses to questions were tabulated and compared using the Chi-squared test. Donors in Xi'an and Canada felt a personal responsibility to donate blood (81·2% vs. 78·0%, P = 0·2057), but Xi'an donors were more likely to consider blood donation a social responsibility (81·7% vs. 45·2%, P < 0·0001). Xi'an donors more often believed that society views donation as a normal activity (98·6% vs. 48·4%, P < 0·0001) and that the social atmosphere promotes donation (90·3% vs. 53·5%, P < 0·0001) and saw greater health benefit (52·3% vs. 12·5%, P < 0·0001). Most Xi'an donors believed in balance between their life force (Qi) and blood (86·7% vs. 49·8%, P < 0·0001) but did not believe blood lost from donating would affect this (0·5% vs. 3·8%, P = 0·01). While traditional Chinese beliefs may not be seen as a barrier among people in Xi'an who donate blood, blood donation is seen differently than by Canadian donors. There is a need for more research specific to China to tailor recruitment strategies.
Publisher: American Society for Microbiology
Date: 23-02-2022
DOI: 10.1128/SPECTRUM.02563-21
Abstract: Here, we describe an approach to estimating seroprevalence in a low prevalence setting when multiple assays are available and yet no known gold standard exists. Because serological studies identify cases through both diagnostic testing and surveillance, and otherwise silent, unrecognized infections, serological data can be used to estimate the true infection fatality ratio of a disease.
Publisher: Wiley
Date: 05-08-2019
DOI: 10.1111/TRF.15470
Abstract: The erythrocytic protozoan parasite Babesia microti, the cause of human babesiosis, is transmitted not only by tick bites but also via blood transfusion. B. microti is endemic in the northeastern/upper midwestern United States, where partial screening of blood donations has been implemented. In Canada, a 2013 study of approximately 14,000 donors found no B. microti antibody-positive s les, suggesting low risk at that time. Between June and October 2018, 50,752 Canadian donations collected from sites near the US border were tested for Babesia nucleic acid by transcription-mediated lification (TMA). Reactive donations were tested for B. microti by IgG immunofluorescence assay and polymerase chain reaction. A subset of 14,758 TMA nonreactive s les was also screened for B. microti antibody. Donors who tested reactive ositive were deferred, asked about risk factors, and were requested to provide a follow-up s le for supplemental testing. One s le from Winnipeg, Manitoba, was TMA and antibody reactive. Of the 14,758 TMA-nonreactive donations tested for antibody, four reactive donations were identified from southwestern Ontario near Lake Erie. None of the interviewed donors remembered any symptoms, likely tick exposure, or relevant travel within Canada or the United States. This is the largest B. microti prevalence study performed in Canada. The results indicate very low prevalence, with only one TMA-confirmed-positive donation of 50,752 tested. This donor was from the only region in Canada where autochthonous infection has been reported. Seropositive donations in southwestern Ontario suggest low prevalence travel should not be ruled out given the proximity to the US border.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.RESUSCITATION.2019.02.035
Abstract: Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) has been reported in in idual studies to significantly increase the rate of bystander CPR and survival from cardiac arrest. We undertook a systematic review and meta-analysis to evaluate the impact of DA-CPR programs on key clinical outcomes following out-of-hospital cardiac arrest. We searched the PubMED, EMBASE, CINAHL, ERIC and Cochrane Central Register of Controlled Trials databases from inception until July 2018. Eligible studies compared systems with and without dispatcher-assisted CPR programs. The results of included studies were classified into 3 categories for the purposes of more accurate analysis: comparison of outcomes in systems with DA-CPR programs, case-based comparison of DA-CPR to bystander CPR, and case-based comparisons of DA-CPR to no CPR before EMS arrival. The GRADE system was used to assess certainty of evidence at an outcome level. We used random-effects models to produce summary effect sizes across all outcomes. Of 5531 citations screened, 33 studies were eligible for inclusion. All included studies were observational. Evidence certainty across all outcomes was assessed as low or very low. In system-level and patient-level comparisons, the provision of DA-CPR compared with no DA-CPR was consistently associated with improved outcome across all analyses. Comparison of DA-CPR to bystander CPR produced conflicting results. Findings were consistent across sensitivity analyses and the pediatric sub-group. These results support the recommendation that dispatchers provide CPR instructions to callers for adults and children with suspected OHCA. Review registration: PROSPERO- CRD42018091427.
Publisher: Wiley
Date: 27-09-2018
DOI: 10.1111/TRF.14941
Abstract: We assessed donor return rates, donation frequency, and factors related to the evolution of ferritin levels 2 years after entering donors into a large operational study of ferritin testing. Ferritin testing was done on donors from representative clinics (n = 12,595). Low-ferritin donors (<25 μg/L) were informed and not called for 6 months to book a donation. Approximately 37% of donors had ferritin retested on a return donation. Return rate and donation frequency were monitored, and a logistic regression model was constructed. The return rate was lower in low-ferritin donors (67% vs. 78%), particularly in women who were first-time donors (36% vs. 61%). Returning low-ferritin donors made fewer donations in the 2 years after notification compared to the 2 years prenotification (4.5 vs. 7.5 for men, 3.0 vs. 5.0 for women), while donation frequency was lower and increased slightly for normal-ferritin donors (4.7 vs. 4.4 for men, 3.6 vs. 3.1 for women). An increased number of donations, shorter interdonation intervals, female sex, and younger age are associated with low ferritin levels on initial and repeat testing. Some recovery of ferritin occurred, but most low-ferritin donors continued to have low or borderline levels on retesting. Informing donors of low ferritin results had a long-lasting impact on return rates and donation frequency, requiring recruitment efforts to maintain adequacy of supply. Increasing the interdonation interval leads to some improvement in ferritin levels more sustained efforts to encourage donors to improve iron intake are needed to achieve long-term benefit.
Publisher: Wiley
Date: 02-12-2020
DOI: 10.1111/TRF.16165
Publisher: Elsevier BV
Date: 07-2022
Publisher: Wiley
Date: 02-2010
DOI: 10.1111/J.1365-3148.2009.00969.X
Abstract: Non-disclosure of deferrable risk has received little attention in the literature. We examined deferrable risk (history of intravenous drug use [IVDU]) and donor attitudes towards truthfulness, the screening process and interpretation of the screening question as well as risk profile. Donors negative for all markers with a self-reported history of IVDU (N = 30) and matched controls were identified from an anonymous mail-out survey. In a separate survey, hepatitis C virus (HCV)-positive donors participated in a telephone interview, from which all those with IVDU history (N = 29) were selected plus matched controls (combined total 59 IVDU, 236 controls). IVDU donors, when compared with matched controls, tended to believe that it is OK not to answer truthfully if one believes that her/his blood is safe (18.6% vs. 4.7%) and that some questions are a little too personal (35.6% vs. 21.7%). IVDU donors were more likely than controls to say they failed to acknowledge screening questions appropriately (23% vs. 2.2%) or to agree that IVDU questions are mainly about recent drug taking or sharing needles (29% vs. 11%) even though the screening question asked about IVDU ever without any such qualifiers. IVDU donors were also more likely to have other lifestyle/risk factors such as history of sex with IVDU (45.5% vs. 1.7%). Donors with deferrable IVDU history may rationalise that revealing their status is not necessary and may misinterpret the question. Failure to acknowledge risk behaviour is complex, and some degree of non-disclosure may be an inherent part of pre-donation screening.
Publisher: Wiley
Date: 04-09-2017
DOI: 10.1111/TRF.14307
Abstract: We compared donor and general population demographics over time to provide insight into current donation patterns and the future adequacy of the blood supply. Seventeen blood center members of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative from 12 countries provided the number of donors and people in the general population by demographic category for 2001 and 2011, changes in age criteria, and percentage of first-time donors. We calculated the median age of donors and the general population and determined the percentage of each group in age and sex cohorts. Age criteria vary, with upper limits recently liberalized in several countries. In 2011, the percentage of first-time donors ranged from 10% to 41%. The median age of the donor and general population increased from 2001 to 2011 in most countries, as did the percentage of the general population over 60. The youngest donor cohort is overrepresented to a variable degree this tendency increased over time. Although still underrepresented, older donors contributed more in 2011. A large middle-aged cohort is aging at a rate exceeding the progression of time, while 25- to 45-year-olds are relatively underrepresented. All participating countries are experiencing aging of their general population. Donor demographics differ substantially between countries this can be only partly explained by population demographics and age criteria. Many countries have an aging middle-aged donor and population cohort and are increasingly relying on their youngest donors to contribute disproportionately to the blood supply.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-12-2019
DOI: 10.1161/CIR.0000000000000734
Abstract: The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research.
Publisher: American Society for Microbiology
Date: 23-02-2022
DOI: 10.1128/SPECTRUM.02262-21
Abstract: In the first 3 months of 2021 as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination was in the initial stages of a mass rollout, Canadian blood donors had various levels of humoral protection against wild-type and variant of concern (VOC) SARS-CoV-2. Very few Canadians would have received a second dose of a SARS-CoV-2 vaccine.
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.TRACLI.2022.06.001
Abstract: Gay, bisexual and other men who have sex with men (gbMSM) were ineligible to donate blood in most countries since the 1980's. In Canada the deferral period has been incrementally decreased from lifetime to male-to-male sex in the last 3 months. Now a few countries have removed the deferral altogether. Risk models have been utilised to estimate the probability of an HIV positive donation being released into the blood supply and to inform incremental changes to the length of the deferral period. Here we use public health data to estimate the risk of HIV if the gbMSM deferral criteria were removed in Canada. We calculate the risk reduction among heterosexuals based on responses to standard risk questions routinely asked of donors. We assume gbMSM will donate at the same rate as heterosexual males. We apply the same risk reduction principle to HIV incidence and prevalence among gbMSM in the general population to evaluate the HIV risk without gbMSM time deferral. We model three scenarios where risk reduction is varied by assumptions about incidence and compliance with deferral criteria. The estimates for all scenarios were not significantly different to the currently observed scenario which predicts a residual risk of 0.02 HIV positive per million donations (95% CI: 0.000006-0.09). The models predict that removing the gbMSM deferral criteria would result in HIV residual risk similar to currently observed.
Publisher: Springer Science and Business Media LLC
Date: 02-11-2020
DOI: 10.1186/S12961-020-00643-4
Abstract: Blood donation policy in Canada for gay, bisexual and other men who have had sex with men (gbMSM) has changed progressively in the last decade from indefinite deferral to 3-month deferral from last male-to-male sex. Driven by safety data and overseen by the national regulator, more inclusive policies continue to redress the disparity in donation for gbMSM. At the same time, the need for source plasma to prepare fractionated blood products is growing worldwide. The collection and processing of source plasma ensures greater safety compared to whole blood donation with respect to transfusion-transmitted infection. This greater safety offers an opportunity to evolve policies for gbMSM from time-based to behaviour-based deferral using revised eligibility criteria. However, changing policies does not in itself necessarily guarantee that gbMSM will donate or that staff in donor clinics are ready to support them to do so. In anticipation of a move to behaviour-based donation screening for gbMSM in Canada, we aim to assess the acceptability of and perceived barriers and enablers to source plasma donation using revised screening criteria for gbMSM among key stakeholders to inform policy implementation strategies. This mixed-methods feasibility study will involve gbMSM and donor centre staff to understand modifiable barriers to implementing more inclusive eligibility criteria. Key informant interviews and surveys will be rooted in the Theoretical Domains Framework to identify modifiable factors associated with source plasma donation motives in gbMSM and training needs in donation centre staff. We will use an integrated knowledge translation approach involving a partnership between researchers, the national blood operator and gbMSM, situating knowledge users as key research team members to ensure their perspectives inform all aspects of the research. Our integrated knowledge translation approach will provide a more comprehensive and collaborative understanding of blood operator and gbMSM needs while accelerating the implementation of study findings. Given the historical backdrop of the decades of exclusion of sexually active gbMSM from blood donation, this study has the potential not only to inform a process and policy for gbMSM to donate source plasma, a blood product, but also offers opportunities for new relationships between these knowledge users.
Publisher: Elsevier BV
Date: 05-2016
Publisher: Wiley
Date: 15-07-2021
DOI: 10.1111/VOX.13176
Abstract: In Canada, men having sex with men (MSM) are deferred for 3 months from last sexual contact to reduce human immunodeficiency virus (HIV) risk to recipients. The aim of this paper was to model the Canadian residual risk of HIV‐positive source plasma incorporating pathogen inactivation (PI) under no MSM deferral scenarios for apheresis plasma donations. A combined Bayesian network (BN) and Monte Carlo approach were implemented to estimate the HIV residual risk under 3‐month deferral compared with no deferral without quarantine scenarios for MSM donors. Models involve the stochastic generation of donation and its infection status based on its corresponding simulated donor profile. Viral load reduction conferred by PI used by source plasma fractionators was simulated. Model parameters were derived from Héma‐Québec and Canadian Blood Services data, viral loads in a large s le of HIV‐positive US blood donors, CSL Behring documentation and from published data. In the most likely scenario for the 3‐month deferral model, there were 2.71 positive donations per 1,000,000 donations (95% confidence interval [CI] 2.63–2.78). For the no‐deferral model, there were 3.01 positive donations per 1,000,000 donations (95% CI 2.94–3.09). For both scenarios, the risk of having an infectious pool was 0 in 300,000 pools (95% CI 0–0.0000123) after consideration of PI. Based on simulation results, there would be a negligible HIV residual risk associated with the removal of a time‐based MSM deferral without quarantine for source plasma incorporating PI.
Publisher: University of Toronto Press Inc. (UTPress)
Date: 09-2022
Abstract: BACKGROUND: Serological assays designed to detect SARS-CoV-2 antibodies are being used in serological surveys and other specialized applications. As a result, and to ensure that the outcomes of serological testing meet high quality standards, evaluations are required to assess the performance of these assays and the proficiency of laboratories performing them. METHODS: A panel of 60 plasma/serum s les from blood donors who had reverse transcriptase–polymerase chain reaction (RT-PCR) confirmed SARS-CoV-2 infections and 21 SARS-CoV-2 negative s les were secured and distributed to interested laboratories within Canada ( n = 30) and the United States ( n = 1). Participating laboratories were asked to provide details on the diagnostic assays used, the platforms the assays were performed on, and the results obtained for each panel s le. Laboratories were blinded with respect to the expected outcomes. RESULTS: The performance of the different assays evaluated was excellent, with the high-throughput platforms of Roche, Ortho, and Siemens demonstrating 100% sensitivity. Most other high-throughput platforms had sensitivities of %, with the exception of the IgG assay using the Abbott ARCHITECT which had an average sensitivity of only 87%. The majority of the high-throughput platforms also demonstrated very good specificities ( %). CONCLUSION: This proficiency study demonstrates that most of the SARS-CoV-2 serological assays utilized by provincial public health or hospital laboratories in Canada have acceptable sensitivity and excellent specificity.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Wiley
Date: 22-10-2021
DOI: 10.1111/TRF.16713
Abstract: This pilot study assesses the ability of plasma collected from Canadian blood donors in the first wave of the SARS‐CoV‐2 pandemic to neutralize later SARS‐CoV‐2 variants of concern (VOCs). A repeated cross‐sectional design was used, and a random cross‐sectional s le of all available Canadian Blood Services retention s les (n = 1500/month) was drawn monthly for April and May of 2020. Qualitative IgG analysis was performed on aliquots of specimens using anti‐spike, anti‐receptor binding domain, and anti‐nucleocapsid protein enzyme‐linked immunosorbent assays as well as the Abbott Architect SARS CoV‐2 IgG assay (Abbott Laboratories) against the anti‐nucleocapsid protein. Selected plasma specimens were then assessed for neutralization against VOCs using pseudotyped lentivirus inhibition assays as well as plaque reduction neutralization test 50% (PRNT 50 ). Six specimens with a high neutralizing titer against wild‐type SARS‐CoV‐2 and three specimens with a low neutralizing titer against wild‐type SARS‐CoV‐2 were chosen for further analysis against VOCs. Four of six high neutralizing titer specimens had a reduced neutralizing capacity against beta VOCs by both neutralization methods. Three of six high neutralizing titer specimens had reduced neutralization capacity against gamma VOCs. This preliminary data can be used as a justification for limiting the use of first wave plasma products in upcoming clinical trials but cannot be used to speculate on general trends in the immunity of Canadian blood donors to SARS‐CoV‐2.
Publisher: Elsevier BV
Date: 05-2022
DOI: 10.1016/J.TRACLI.2021.11.002
Abstract: Blood donors with high Hb are often deferred for the presumed risk of polycythemia vera (PV). However, adequate data to substantiate or refute this hypothesis is lacking. We conducted an observational study on blood donors found to have high hemoglobin (Hb≥18g/dL) during the pre-donation screening process using a portable hemoglobinometer at our blood center for four months. We adopted a cost effective methodology wherein a questionnaire was used to elicit the secondary causative factors of high hemoglobin and a complete blood count test to observe the blood cell parameters and JAK2V617F mutation test was performed in a subset of donors lacking secondary erythrocytosis (SE) history. Of the total 7076 donors enrolled, 112 male donors (1.58%) had high hemoglobin. The majority (70.4%) were repeat donors with mean age of 31.4 years. About 61% of the donors had attributable factors for SE like smoking, occupational exposure to carbon monoxide. The mean hemoglobin value of capillary and venous hemoglobin demonstrated a statistically significant difference (P<0.05) where 2.7% of donors had venous Hb<18g/dL. The hematological profile of all the donors showed increased RBC but normal platelet and WBC count. Of 24 donors included for the JAK2V617F test, none had a positive report. This study suggests high hemoglobin in blood donors is less likely due to PV. Hence, re-considering their deferral may help alleviate donor anxiety and allow donor return. However, multi-centric studies are required to develop consensus statements on PV risk status and blood donation eligibility.
Publisher: Wiley
Date: 26-06-2006
Publisher: Wiley
Date: 31-12-2015
DOI: 10.1111/TRF.13445
Abstract: The deferral for men who have sex with men (MSM) changed from a permanent deferral since 1977 to a 5-year deferral on July 22, 2013, in Canada. We assessed the impact on safety and adequacy of the blood supply at Canadian Blood Services. Human immunodeficiency virus (HIV) rates were monitored from January 1, 2010, to July 21, 2015. Risk factors were assessed in notification interviews. Anonymous online surveys of male whole blood donors assessed compliance before and after implementation. HIV rates were 0.2, 0.5, and 0.51 per 100,000 donations in 2010 to 2012 they were 0.54 and 0.22 in the first and second years after implementation (p = 0.8). Of four male HIV-positive donors after implementation, three denied risk factors and one knew he had HIV. Before implementation 9669 of 19,437 (49.7%) donors participated in the survey, and after implementation, 6881 of 18,934 (36.3%). Before implementation 0.67% of male donors were noncompliant, and after implementation, 0.44%. There was no difference before versus after implementation in male donors with MSM history in the past 5 years (0.37% vs. 0.43%, p = 0.54). After implementation, eligible MSM donors increased (0.42% vs. 0.66%, p = 0.04), with approximately 500 more donors in 2014. Implementation of a 5-year deferral for MSM had no impact on HIV rates in 2 years of postimplementation monitoring. Donor compliance improved after implementation due to MSM donors who were previously ineligible becoming eligible. There was no change in the percentage of male donors with recent male partners but there was a modest increase in eligible MSM in the donor pool.
Publisher: Wiley
Date: 14-07-2022
DOI: 10.1111/TRF.17000
Abstract: Canadian Blood Services introduced new eligibility criteria that allows some sexually active gay, bisexual, and other men who have sex with men (gbMSM) to donate source plasma, marking a significant change from time‐based deferral criteria. We aimed to identify potential barriers and enablers to implementing the new criteria from the perspective of donor center staff. We conducted Theoretical Domains Framework‐informed interviews with staff from two source plasma donation centers in Canada. We completed 28 interviews between June 2020 and April 2021. Three themes representing eight domains captured key tensions. Valuing inclusive eligibility criteria : staff support inclusive criteria many were concerned the new criteria remained discriminatory. Investing in positive donor experiences : staff wished to foster positive donor experiences however, they worried gbMSM donors would express anger and disappointment regarding the new criteria, staff would experience unease over using stigmatizing criteria and convey nonverbal cues of discomfort, and recurring plasma donors may behave inappropriately. Supporting education , training , and transparency of eligibility criteria : participants believed providing in‐person training (i.e., to explain criteria rationale, address discomfort, practice responding to donor questions) and ensuring donors and the public were well‐informed of the upcoming changes would improve implementation. Participant views emphasize the importance of supporting staff through training and transparent communication to optimize the delivery of world‐class equitable care for a new cohort of donors who have previously been excluded from plasma donation. Findings inform which staff supports to consider to improve implementation as policies continue to shift internationally.
Publisher: Elsevier BV
Date: 07-2023
Publisher: Wiley
Date: 23-01-2009
DOI: 10.1111/J.1537-2995.2008.01973.X
Abstract: The expected donor loss from recent implementation of antibody to hepatitis B core antigen (anti-HBc) testing in Canada was uncertain but potentially significant based on US experience. To reduce donor loss from false-reactive tests, repeat-reactive donors without other evidence of infection were eligible to return. The aim was to evaluate the impact of anti-HBc testing on donor loss and to evaluate the effectiveness of this policy. For each donor in the first year of implementation (April 9, 2005-April 8, 2006) repeat-reactive for the presence of anti-HBc only but eligible to return (screening test for hepatitis B surface antigen-negative, plus not reactive to antibody to hepatitis B surface antigen [anti-HBs] and hepatitis B virus [HBV] DNA supplemental tests), 10 matched donors not reactive to the anti-HBc assay were selected. Return rates over 2 years were compared using conditional logistic regression. Testing outcomes were tabulated. Over the first year of testing, 412,236 donors (951,423 donations) were tested for anti-HBc, and 4,489 donors were repeat-reactive (1.3% of first-time donors, 1.0% of repeat donors). Of these 85.6 percent were also reactive for the presence of anti-HBs and/or HBV DNA supplemental tests leaving less than 15 percent eligible to return, of whom 73 percent returned (vs. 90% of controls, p < 0.001). Of the 300 anti-HBc repeat-reactive returning donors, 74 percent were anti-HBc repeat-reactive again (thus permanently deferred), 19 percent were deferred for other reasons versus 14 percent of controls (p < 0.05), and 7 percent (21 donors) did not react and were eligible to continue donating. Most donors repeat-reactive for the presence of anti-HBc likely have past exposure to HBV. If eligible, most are willing to return, but likely to test anti-HBc repeat-reactive again.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2000
DOI: 10.1097/00005344-200008000-00006
Abstract: Vascular wall function was assessed in obese insulin-resistant (cp/cp) and lean normal (+/?), male and female, JCR:LA-cp rats. Both male and female cp/cp rats showed enhanced maximum contractility in response to norepinephrine impaired smooth muscle in response to sodium nitroprusside, a nitric oxide (NO) donor and impaired relaxation in response to acetylcholine (ACh), compared with their lean counterparts. The abnormalities were similar in male and female cp/cp rats. The NO synthase inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME), inhibited ACh-mediated relaxation significantly in male rats, both cp/cp and +/?. The inhibition of ACh-mediated relaxation by L-NAME in +/? females was less, with no reduction in maximal relaxation, and was absent in cp/cp females. These effects suggest that the relative importance of NO in the endothelial modulation of smooth muscle contractility is greater in male rats. The results are consistent with a decreased role for endothelial NO in the cp/cp rats of both sexes and a reduction in NO-independent cholinergic relaxation in the male cp/cp rat. This NO-independent mechanism is not affected in the female cp/cp rats. The relatively small differences between males and females in smooth muscle cell and vascular function may contribute to sex-related differences in the atherogenesis, vasospasm, and ischemic damage associated with the obese insulin-resistant state.
Publisher: Wiley
Date: 15-06-2022
DOI: 10.1111/VOX.13328
Abstract: To protect transfusion recipients from transfusion‐transmissible infections, blood donors are deferred from donating after recent tattooing or piercing. To explore to what extent and how this deferral impacts donor availability, we performed an international study to investigate how many donors were deferred for a recent tattoo or piercing and how many of these donors returned to donate. We surveyed blood centre members of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative and the European Blood Alliance Donor Studies Working Group on their numbers of donations, tattoo and piercing deferrals, and return rates in the year 2017. Eight blood centres participated. Overall, deferral rates were lower for repeat donors compared to new donors. Repeat donors were more likely to return than new donors. Women and young donors were more often deferred than male and older donors. Men were more demotivated by tattoo or piercing deferral, resulting in lower return rates compared to women. Return rates differed greatly between blood centres. Tattoo and piercing deferrals lead to missed donations and result in lower return rates. However, the numbers vary largely internationally, probably due to cultural and policy differences. Shortening deferral periods after tattooing or piercing may reduce the impact on donor availability, which should be investigated in single‐centre studies.
Publisher: Portland Press Ltd.
Date: 11-1996
DOI: 10.1042/CS0910567
Abstract: 1. We measured endothelium-dependent and independent dilatation of forearm resistance arteries in 29 men with diet-treated non-insulin-dependent diabetes mellitus and 18 age- and sex-matched control subjects. None of the diabetic patients had hypercholesterolaemia, overt hypertension or microproteinuria. 2. We examined endogenous and exogenous nitric oxide-mediated vasodilatation by measuring forearm blood flow with venous occlusive plethysmography after administration of acetylcholine (7.5 and 15 μg/min) and sodium nitroprusside (3 and 10 μg/min), respectively, into the brachial artery. NG-monomethyl-l-arginine was also infused to study the inhibition of basal and stimulated release of nitric oxide. 3. The vasodilatory response to acetylcholine, expressed as area under curve, was significantly decreased in the diabetic patients compared with the control subjects (P = 0.019). NG-monomethyl-l-arginine significantly reduced basal (P & 0.001) and acetylcholine-stimulated blood flow (P & 0.02) in both groups. The vasodilatory response (also expressed as area under curve) to sodium nitroprusside was significantly less (P = 0.044) in the diabetic patients than in the control subjects. 4. In the diabetic patients, impaired vasodilatory responses to acetylcholine were significantly correlated with higher serum triacylglycerols (P = 0.048) and lower high-density lipoprotein-cholesterol concentrations (P = 0.007) the association with high-density lipoprotein was independent of age, glycated haemoglobin and blood pressure. Sodium nitroprusside responses were not correlated with lipid and lipoprotein concentrations. 5. We conclude that there is impaired endothelial and smooth muscle cell function in men with diet-treated non-insulin-dependent diabetes mellitus uncomplicated by overt hypertension or microproteinuria. Endothelial dysfunction may be related to diabetic dyslipidaemia and associated metabolic disturbances.
Publisher: Wiley
Date: 29-11-2006
DOI: 10.1111/J.1537-2995.2006.01048.X
Abstract: The donor health assessment questionnaire (DHAQ) plays an important role in ensuring blood safety. The Canadian DHAQ has been developed over many years on an ad hoc basis and has never been evaluated in light of cognitive science principles. In addition, donor attitudes about its mode of administration have not been assessed. Between May and August 2005, a total of 456 donors participated in the study by completing the DHAQ, followed by a short, scripted interview assessing recall (as an indicator of attention to the questions) of 17 specific items queried on the DHAQ and attitudes toward interviewer or self-administration of the DHAQ. Overall, 7.5 percent of donors were able to correctly identify all 17 items. Recall was best for questions asked as in idual items (87%-99%) and decreased substantially for items that are part of a list (55%-91%). Position effects were demonstrated, with items at the end of a list being the most frequently forgotten. Twenty percent of repeat donors favored the current practice of interviewer administration of high-risk questions, whereas 80 percent were neutral or favored self-administration. The current format of the Canadian DHAQ is not optimal for donor attention to specific questions asked as part of a list. The majority of repeat donors are ready for a change in the method of administration of the DHAQ. Studies on donor recall may help guide evidence-based changes to the DHAQ.
Publisher: Elsevier BV
Date: 12-1995
DOI: 10.1016/0168-8227(95)01162-5
Abstract: Insulin-dependent diabetics have a greatly increased risk of developing premature coronary artery disease which is not entirely explained by known risk factors. A possible explanation may be enhanced oxidative modification of low density lipoprotein (LDL). The aim of this study was to determine firstly, whether or not LDL from moderately well controlled type 1 diabetics is more readily oxidisable than LDL from healthy non-diabetics and, secondly, to assess whether potential predictors of LDL oxidisability differ between type 1 diabetics and controls. Twenty type 1 diabetic men were carefully matched with healthy non-diabetic men on the basis of age and body mass index and each pair attended the department on the same morning for blood s ling. LDL oxidisability was assessed using both copper in PBS, 15 and 30 mM glucose, and with AAPH. There was no difference between type 1 diabetics and controls in the susceptibility of the LDL to either copper-dependent or non-transition metal-dependent oxidation. Furthermore, there was no difference between the groups for LDL vitamin E content, LDL fatty acid composition in cholesteryl esters, triglycerides or phospholipids, or LDL copper reductive capacity, but LDL glycation was elevated in the IDDM subjects. Given the absence of increased LDL oxidisability in these subjects, the recommendation of vitamin E supplementation in type 1 diabetics should be considered a secondary priority to achieving adequate glucose control.
Publisher: Wiley
Date: 14-12-2020
DOI: 10.1111/TRF.15627
Abstract: This study examined the impact of age and sex of first-time donors who had not experienced an adverse event or deferral on their likelihood of and time to return. On behalf of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative, international blood collection agencies (BCAs) were invited to provide data on first-time whole blood donors in 2014, including initial presentation date, collection site type, age, sex, blood type, return to donate within 24 months (yes/no), and subsequent presentation date. Eight BCAs contributed 706,789 records. The overall odds of returning to donate were slightly lower in female versus male donors, and the overall age trend was U-shaped with younger and older donors having higher odds for returning relative to middle-aged donors. However, variations by BCA were observed. Specifically, in three BCAs, women had higher odds of returning to donate than men. Further, while across seven BCAs the smallest cohort of older first-time donors returned at a higher rate and returned more quickly than middle-aged first-time donors, the behavior of younger donors varied substantially between BCAs. While older first-time donors are more likely to return and return more quickly than middle-aged donors they make up only a small proportion of first-time donors, whereas the larger group of younger donors exhibits less clear patterns of return compared to middle-aged donors. Further research is needed to determine whether targeting the recruitment of older donors or bolstering retention of middle-aged donors would be most effective in maintaining the blood supply.
Publisher: Wiley
Date: 31-01-2012
DOI: 10.1111/J.1423-0410.2012.01584.X
Abstract: Estimates of the viral residual risk should be updated to reflect current incidence of infection in blood donors. Incidence rates were estimated for allogeneic whole-blood donations made to Canadian Blood Services from 2006 to 2009 based on transmissible disease conversions of repeat donations within a 3-year period. Residual risk was estimated as the incidence multiplied by the window period. The residual risk of HIV was 1 per 8 million donations, HCV 1 per 6·7 million donations and HBV 1 per 1·7 million donations. The residual risk remains low and has decreased for HCV since our previous estimates due to reduced incidence.
Publisher: Wiley
Date: 31-07-2012
Publisher: Wiley
Date: 09-11-2020
DOI: 10.1111/VOX.12995
Publisher: Wiley
Date: 04-09-2018
DOI: 10.1111/VOXS.12446
Publisher: Wiley
Date: 06-06-2007
DOI: 10.1111/J.1537-2995.2007.01329.X
Abstract: The Canadian donor health assessment questionnaire (DHAQ) has developed gradually over many years. The purpose of this study was to determine whether the format and method of administration of the DHAQ influences donor attentiveness. Between May 2004 and September 2005, a total of 1,397 donors participated in the study by completing the DHAQ by one of three methods: the current Canadian Blood Services (CBS) format and method of administration, which is partly self-administered and partly interviewer-administered (Method 1) the DHAQ reformatted to the AABB Uniform Donor Health Questionnaire format and self-administered (Method 2) and an audiovisual computer-assisted self-interview (CASI Method 3). This was followed by a short, scripted interview assessing recall of 17 specific items queried on the DHAQ. Time to completion of the DHAQ and degree of familiarity with computer use were also assessed. The percentages of donors identifying all 17 items correctly were 9.4, 20.9, and 34.8 percent and the mean percentages recall of items were 53.9, 56.0, and 69.8 percent with DHAQ administration Methods 1, 2, and 3, respectively (p < 0.0001). This difference was largely attributable to the poor recall of items queried as part of a list in Method 1. Mean times to complete the DHAQ were 3.1, 3.8, and 8.1 minutes for Methods 1, 2, and 3, respectively. More than 95 percent of donors had used a personal computer in the past year. The current format of the Canadian DHAQ is not optimal for donor attention to specific questions asked as part of a list. Attention was improved by use of AABB uniform donor history questionnaire format and was best with use of a CASI format.
Publisher: Wiley
Date: 21-11-2016
DOI: 10.1111/VOXS.12327
Publisher: Wiley
Date: 16-05-2023
DOI: 10.1111/VOX.13443
Abstract: In Canada, the time deferral for gay, bisexual and other men who have sex with men (gbMSM) to donate blood has gradually decreased. In September 2022, this deferral was replaced with sexual behaviour‐based screening for all donors. We investigate how data from targeted research programmes addressed knowledge gaps to support this change. We conducted a scoping review describing the Canadian literature available before the research programmes relating to (1) behavioural indicators of HIV risk and (2) attitudes to blood donation among gbMSM, current donors and the general population. We summarize the targeted research programmes, their outputs and impact to date. For question 1, five projects met inclusion criteria. For question 2, three articles met inclusion criteria. Knowledge gaps identified were insufficient evidence of HIV incidence in gbMSM who met other donor eligibility criteria and scant data on opinions and views of blood donation and screening criteria for sexual risk behaviours. The research programmes funded 19 projects at 11 different research sites involving over 100 in idual researchers/collaborators resulting in 19 peer‐reviewed publications to date. Leveraging existing gbMSM cohorts yielded relevant HIV incidence data to inform safety modelling studies. Findings indicated that sexual behaviour‐based screening was acceptable to gbMSM and donors, and donor discomfort around specific questions could be mitigated with clear explanations. Targeted research programmes filled critical knowledge gaps and informed a change to gender‐neutral, sexual behaviour‐based screening for all donors. Findings supported successful implementation of these changes with research‐informed staff training.
No related grants have been discovered for Sheila O'Brien.